Hi all, long time lurker here and first time posting... I got into flight simming with Sublogic's Flight Simulator II on my beloved Commodore 64 and then Flight Unlimited on PC before I stepped away. Fast forward to 2019 and the introduction of MSFS and all its revolutionary advancements got me really interested again and have been perusing this amazing community on avsim regularly :) Hoping to get a new PC soon and jump on MSFS after SU8/SU9 and wanted to find out more the upcoming CFD and physics enhancements.

 

From what I understand, the core flight model and physics as it stands today (https://docs.flightsimulator.com/html/index.htm#t=Additional_Information%2FFlight_Model_Physics.htm) are already much improved from FSX, but a fair amount of the default planes as provided in the product are not fleshed out enough and/or configured as good as they could be in order to take advantage of the flight model. However, certain 3rd party add-ons have shown what is possible in terms of providing realistic flying experiences such as the DC6, Kodiak, etc. This year looks to be ripe for the arrival of more complex aircraft and hopefully will continue to prove that the core flight model is indeed sound (AFAIK the Fenix, PMDG, etc are all using/extending the core flight model even though systems ops are outside the sim).  One area of the flight model that definitely needs fixing/improving is the ground physics/interactions, and that's been acknowledged by Asobo I believe... So that's all what I've gathered from all my reading here on avsim and other communities, but happy to be corrected :)

 

Based on what was shown in the recent Q&A and also in the aerodyamics feature highlight https://www.youtube.com/watch?v=Ndl07_7PsWg , looks like the coming CFD and physics enhancements will only further advance what's already there.. and I'm wondering if the experts in the know here, and especially anyone from Working Title, FBW, SWS, etc could comment further on what exact improvements this practically means for GA and tubeliners? Even non-prop aircraft stand to improve in terms of aerodynamics right? Especially with the coming CFD in SU9, how does that compare to what something like Flight Unlimited provided? i.e. Seamus Blackley's physics implementation in FU was something to behold. Anyhow, sorry for the long post, was just hoping to hear from the experts about the coming improvements, and hopefully spur some useful discussion :)

You probably have already watched some Youtube videos of aircraft flying around in MSFS. Large planes using avionics to maneuver artificially probably won't tell much about of how MSFS flies. I would look at smaller planes being manually controlled, such as AvAngels videos to get the basic idea.

Here's the mods for flight models on fs.to:

https://flightsim.to/discover/flight model

 

There may be comments on each page. And youtube may have videos using the name of a particular mod where the youtuber makes comments about that flight model mod.

I am happy with all the default flight models of every Asobo plane I have flown. Some of the 3rd party flight models however seem to me that they were designed as a challenge to the buyer: Let's see you fly this!!

In the real world marketplace, planes with difficult handling don't usually succeed. But gamers (as opposed to simmers) seem to want a bigger challenge then real life offers in order to make it more interesting and worth their time.

 

Welcome !

Your description of how you see MFS pretty much mirrors mine. Not being a developer I would nonetheless like to comment on some of your points, starting with the shared respect / recognition for what Seamus offered some of us back in 1995 - Flight Unlimited 1. Unfortunately although still very good, AFAIK FU2 and FU3 shared an FDM which was not the original design of Seamus, and I did notice the differences in behaviour of the aerobatics and glider aircraft between the initial tittle and the following two, as well as some innacuracies that plagued even the "Cessna" and other GA in those tittles and weren't noticeable n Flight Unlkimited "1".

Micrsosoft "killed" some projects like FU, Propilot and even Fly! due to their huge resources compared to those of the teams behind such projects.

You surely know only too well the lead designer behind FU3 - Peter James - who became a bizz jet pilot later and I believe is still working as a pilot, at least last time I read from him.

These projects were all innovative, each on their own. Flight Unlimited was probably my preferred ever civil flight simulator, although by the time it was released I was already veering towards a phase of my simmer life where I preferred to play being an airline pilot - reason why that "Captains..." say from a well known lead producer of add-on airliners for Flight Simulator (snce fs9 ) irritates me like the hell... Weather modelling and ground physics - a major limitation in today's MFS physics modelling that I believe ASOBO already acknowledged and promissed to further enhance... - were only two of the excellent features that made Flight Unlimited ( all versions ) so different from the competition. Propilot created an integrated ATC environment - or was moving in that direction, and Fly! was unique also in some aspects, like systems modelling and scenery. Actually that same guy who sells and lives a wealthy live out of his msfs/p3d products started with a Boeing 767, and was going to start a 757 project when they moved to fs2004 😕 abandoning Fly! 2 altogether...

Well, this turn around instead of killing other projects, MS decided to buy / integrate a sofware house that was already doing well in the production of simulation games, like "The Crew 2", and ASOBO has a growing Team dedicated to MFS only, something that probably not yet as big as "The Aces Game Studio" could easily grow even bigger ( ? ).

I am 100% with you in your observations about the present weak points of MFS, but at the same time I somehow have some faith in their - ASOBO - dedication to making MFS a really interesting and rich flight simulation. In the end I believe it's going to be a Win-Win oucome for a simmer who shares the deepest respect for yet another Team, specially it's Leader Austin Meyer - X-Plane, bringing XP12 this year ( I guess... ) Between the two tittles I am sure I will find more than reasons to spend my "Captains" ( disgusting... ) time in front of a desktop 🙂

 

Edited February 22, 20224 yr by jcomm

19 hours ago, lwt1971 said:

I'm wondering if the experts in the know here, and especially anyone from Working Title, FBW, SWS, etc could comment further on what exact improvements this practically means for GA and tubeliners? Even non-prop aircraft stand to improve in terms of aerodynamics right? Especially with the coming CFD in SU9, how does that compare to what something like Flight Unlimited provided? i.e. Seamus Blackley's physics implementation in FU was something to behold. Anyhow, sorry for the long post, was just hoping to hear from the experts about the coming improvements, and hopefully spur some useful discussion 🙂

One of the initial promo video previews from the days prior to the release of MSFS concerned the better aerodynamics, and I recall it showing the visual representations of what the airflow was doing and how it would take into account things like form drag and such, rather than simply being a bunch of lookup tables like the preceding MS flight sims and their derivatives, and that was what personally got me excited about it far more than all the eye candy which everyone else seemed to be drooling over more than anything else. As it turned out, this feature has been a long time coming, but now that it is on the way, I'm hoping that initial excitement might actually have some meat on the bones so to speak, because whilst eye candy is nice, we are talking about a flight simulator, so the really important thing is how it simulates flight.

Specifically, since in real life I mostly fly gliders, what appealed to me is that it would make flying these in a sim a much more realistic experience. Anyone who flies gliders will know two things about what you have to consider when flying those things: Because they have a long wingspan, there is a good deal of adverse yaw with them, and this is compounded by the fact that there is no propwash in a glider acting on the tailplane. What this means in practical terms, is that in a glider, you have to basically shove the rudder pedal through the floor to get the thing into a turn, and then when it is in a turn, you are usually over at a pretty steep bank angle to stay tight when circling in a thermal, which means you have to start using the elevator as a rudder and the rudder as an elevator to some extent, so there is a lot of back and forth on the rudder pedal to keep it going where you want it to go.

It's worth bearing in mind too that the other things which have a long wingspan, are airliners, so whilst you don't really chuck these things around, they do still have quite a lot of adverse yaw, meaning what you do with the rudder is fairly important. What is also important of course, is that you don't give things a bootful of full rudder at high airspeeds, since this imparts a massive amount of sideways force on the vertical stabiliser, which can, if you overdo it, even break the tail off the thing. This has really happened a few times with airliners, most notably with the Airbus A300 of American Airlines which crashed in Queens, NYC in 2001 after the pilot got really heavy on the rudder, kicking it back and forth and effectively snapping all of the bolts holding the tailfin onto the thing by having levered them back and forth rapidly in the same way that you do when trying to snap a twig.

So in short, I think it means having to fly things more relaistically.

13 hours ago, Fielder said:

I am happy with all the default flight models of every Asobo plane I have flown. Some of the 3rd party flight models however seem to me that they were designed as a challenge to the buyer:

 

Thanks Fielder, all good points! Ya from what I can see based on reviews the default Cessnas are quite good and can only get better as they are updated to take advantage of the coming CFD and prop physics improvements. I've been lurking and reading various forums and communities over the last year+ and it seems that a common misconception in some circles (or talking point lol from those more partial to other sims) is that MSFS is sub-par when it comes to flight modelling and aerodynamics, and from what I can see that's due to the various default aircraft not being configured properly to take full advantage of the new MSFS flight model. But 3rd party offerings like the DC6 and Kodiak prove otherwise, and hopefully the bigger and more complex aircraft coming soon will show this too.

6 hours ago, Chock said:

One of the initial promo video previews from the days prior to the release of MSFS concerned the better aerodynamics, and I recall it showing the visual representations of what the airflow was doing and how it would take into account things like form drag and such, rather than simply being a bunch of lookup tables like the preceding MS flight sims and their derivatives, and that was what personally got me excited about it far more than all the eye candy which everyone else seemed to be drooling over more than anything else. As it turned out, this feature has been a long time coming, but now that it is on the way, I'm hoping that initial excitement might actually have some meat on the bones so to speak, because whilst eye candy is nice, we are talking about a flight simulator, so the really important thing is how it simulates flight.

Absolutely agree Chock, and thanks for your great insights as always. Hopefully with SU9 and beyond MSFS will be in a place where this goal is closer to reality, especially with 3rd party aircraft which can fully take advantage beyond what the default ones do.. it would be great to be able to describe an aircraft's geometry along with other vital attributes such that it behaves sufficiently close to reality, to the point where (like with Flight Unlimited's physics calculations) even if one defines a chair or other such object and then throw it into the sim it will behave and fly/not-fly somewhat like the real object would :)

On a related note, Rob Randazzo over at the PMDG forum posted this recently in response to someone complaining about MSFS's default aircrafts' handling: https://forum.pmdg.com/forum/main-forum/general-discussion-news-and-announcements/162166-19feb22-development-update-pmdg-737-for-msfs-beta-testing-continues-how-does-it-look?p=162845#post162845
 

Quote

You will really like this. It flies significantly more nicely and realistically than other platforms we have worked with. You have to account for thrust coupling now too... I can't wait to get the 747 into this platform. Finally I'll be able to teach you guys some high order handling techniques for under-slung jets. These things just weren't possible in P3D. - RSR

 

31 minutes ago, lwt1971 said:

On a related note, Rob Randazzo over at the PMDG forum posted this recently in response to someone complaining about MSFS's default aircrafts' handling: https://forum.pmdg.com/forum/main-forum/general-discussion-news-and-announcements/162166-19feb22-development-update-pmdg-737-for-msfs-beta-testing-continues-how-does-it-look?p=162845#post162845
 

Based on the changes I have seen Asobo make on MSFS so far regarding the flight modelling, it appears that MSFS is already superior and more advanced than P3D when it concerns the flight modelling.

10 hours ago, Chock said:

As it turned out, this feature has been a long time coming

Are you certain about that? It is my understanding that this feature was there from the beginning, especially from what I've seen in the SDK documentation at that time (around start of 2021). You basically had to specify the geometric shapes of the aircraft in the flight_model.cfg file and the simulator runs a simplified CFD simulation on that.

Only thing is, that this was far from polished or detailed (different airfoils) and the prop simulation did not utilize it at all (still being the FSX table-data).

Edited February 22, 20224 yr by tweekz

1 hour ago, abrams_tank said:

Based on the changes I have seen Asobo make on MSFS so far regarding the flight modelling, it appears that MSFS is already superior and more advanced than P3D when it concerns the flight modelling.

I'm afraid many make the mistake of assuming that just because certain parameters have been opened up or implemented by any core developer, that equals ALL flight models are going to be better. That is unfortunately not true. As an example, a well tuned and carefully edited flight model from an aircraft released in 2009 for FSX will still fly and handle better than an aircraft made for MSFS that has the POTENTIAL to handle well, but doesn't because the person tuning it hasn't got a clue what they are doing. Flight model authenticity or, in plain language, an aircraft that "feels" right, is not really a function of available parameters so much as how well the available parameters have been tuned.

There are many good pilots who despite their talent do not really understand, or at least do not think deeply about, what happens to a given aircraft when a control is moved. Many real pilots who are also sim pilots seem to be very forgiving when it comes to control. Many seem to make unconscious adjustments in their handling movements to compensate for inherently poor reactions by the sim aircraft. The overwhelming commonality in this regard is the gross over-sensitivity in pitch control of particularly small aircraft.

The other point to make is that in PRACTICE rather than in theory, I have yet to see a single aspect of Asobo's new fangled (so claimed) aerodynamic enhancements that have yielded any results that are tangibly better than what was possible in FSX (2006) and even FS9 (2004) from well over 15 years ago. I'm not saying this to be awkward or controversial, but to be truthful. I can give many examples but for starters I'll give a few here:

It became very clear to me that before recent updates, and for over a year and 3 months, almost all FS2020 aircraft were incapable of editable adverse yaw. There was a small amount but I believe that was set by default. It certainly was not editable and I discovered that the vast majority of parameters listed in the flight_model.cfg files were non-functioning, include the so-described adverse yaw params listed and commented by Asobo. This is clearly the case as Asobo has now had to implement aileron assymetrical drag as an added in effect just recently. But FSX ALREADY had at least three different ways of implementing adverse yaw in three distinct ways, and indeed was almost infinitely more tweakable than what we have now in MSFS.

Now lets look at wing drops and spins. I was as thrilled as anyone to hear at the time of release that Asobo was implementing a radically new flight model core which dynamically reacted in real time to multiple "lift points" along the entire two wings and other surfaces. Fantastic news. So why then does Asobo still use a crude and one-shot "trigger"  to promote a wing drop at high angles of attack? Wait a minute! This is nothing more than a hacked version of the very same parameter in FSX and FS9 over 20 years ago. This crude parameter was put there to promote roll instability near the stall which often resulted in an oscillation in roll, often leading to a potential spin. This crude mechanism had to be put there because an "artificial" method had to be used, there being no proper lift complexity in the core flight model to trigger this response. Now, if Asobo really did have proper mutliple lift points dynamically acting upon surfaces as they claim, why are they falling back on a crude hack.

For those interested the "hack" parameter concerned is in FSX table 1538 Cl_r(alpha) Roll rate vs AoA. The explanation of this param boils down to this: Two crude spikes on a graph trigger random and opposite roll movements dependent on the angle of attack of the wing in order to produce a rocking movement in roll. At the extreme of one direction rocking movement a kick in rudder in the same direction might promote a spin. This is exactly the hack Asobo uses in its "rocking wing" effect shortly after or before a stall. But in MSFS it is not as controllable as in FSX because it lacks at least six additional editable parameters available in the FSX version.

Another thing I do not quite understand: Asobo recently announced that it was going to start implementing accurate feathering of props, as though this was a mind-boggling, tremendous innovation. They backed this up with yet more claims of multiple dynamic lift and drag points all over the props with their array of green lines etc. But hang on. At Realair we implemented convincing prop feathering as far back as 2011 or thereabouts, and we didn't need over-complicated multiple prop lift points. We just overcame a few FSX and later P3D limitations and made it happen, as did quite a few other developers. So it is not a special thing but a very basic item on a list of other basic flight model items yet to be implemented, but were available in FSX many years ago. 

Sorry if this comes over as negative. I'm full of admiration for the 3d aircraft modelling in MSFS and there are some stunning landscapes, regions and sceneries. But the idea that Asobo is somehow revolutionary with their very impressive PR relating to aerodynamics  falls a bit flat for me. Most of the innovations they discuss were already implemented in many other sims (not just the big three) years and years ago.

Edited February 22, 20224 yr by robert young

7 minutes ago, robert young said:

I'm afraid many make the mistake of assuming that just because certain parameters have been opened up or implemented by any core developer, that equals ALL flight models are going to be better. That is unfortunately not true. As an example, a well tuned and carefully edited flight model from an aircraft released in 2009 for FSX will still fly and handle better than an aircraft made for MSFS that has the POTENTIAL to handle well, but doesn't because the person tuning it hasn't got a clue what they are doing. Flight model authenticity or, in plain language, an aircraft that "feels" right, is not really a function of available parameters so much as how well the available parameters have been tuned.

There are many good pilots who despite their talent do not really understand, or at least do not think deeply about, what happens to a given aircraft when a control is moved. Many real pilots who are also sim pilots seem to be very forgiving when it comes to control. Many seem to make unconscious adjustments in their handling movements to compensate for inherently poor reactions by the sim aircraft. The overwhelming commonality in this regard is the gross over-sensitivity in pitch control of particularly small aircraft.

The other point to make is that in PRACTICE rather than in theory, I have yet to see a single aspect of Asobo's new fangled (so claimed) aerodynamic enhancements that have yielded any results that are tangibly better than what was possible in FSX (2006) and even FS9 (2004) from well over 15 years ago. I'm not saying this to be awkward or controversial, but to be truthful. I can give many examples but for starters I'll give a few here:

It became very clear to me that before recent updates, and for over a year and 3 months, almost all FS2020 aircraft were incapable of editable adverse yaw. There was a small amount but I believe that was set by default. It certainly was not editable and I discovered that the vast majority of parameters listed in the flight_model.cfg files were non-functioning, include the so-described adverse yaw params listed and commented by Asobo. This is clearly the case as Asobo has now had to implement aileron assymetrical drag as an added in effect just recently. But FSX ALREADY had at least three different ways of implementing adverse yaw in three distinct ways, and indeed was almost infinitely more tweakable than what we have now in MSFS.

Now lets look at wing drops and spins. I was as thrilled as anyone to hear at the time of release that Asobo was implementing a radically new flight model core which dynamically reacted in real time to multiple "lift points" along the entire two wings and other surfaces. Fantastic news. So why then does Asobo still use a crude and one-shot "trigger"  to promote a wing drop at high angles of attack? Wait a minute! This is nothing more than a hacked version of the very same parameter in FSX and FS9 over 20 years ago. This crude parameter was put there to promote roll instability near the stall which often resulted in an oscillation in roll, often leading to a potential spin. This crude mechanism had to be put there because an "artificial" method had to be used, there being no proper lift complexity in the core flight model to trigger this response. Now, if Asobo really did have proper mutliple lift points dynamically acting upon surfaces as they claim, why are they falling back on a crude hack.

Another thing I do not quite understand: Asobo recently announced that it was going to start implementing accurate feathering of props, as though this was a mind-boggling, tremendous innovation. They backed this up with yet more claims of multiple dynamic lift and drag points all over the props with their array of green lines etc. But hang on. We (at RealAir) implemented convincing prop feathering I think in 2011 or thereabouts, and we didn't need over-complicated multiple prop lift points. We just overcame a few FSX and later P3D limitations and made it happen, as did quite a few other developers. So it is not a special thing but a very basic item on a list of other basic flight model items yet to be implemented, but were available in FSX many years ago. 

Sorry if this comes over as negative. I'm full of admiration for the 3d aircraft modelling in MSFS and there are some stunning landscapes, regions and sceneries. But the idea that Asobo is somehow revolutionary with their very impressive PR relating to aerodynamics  falls a bit flat for me. Most of the innovations they discuss were already implemented in many other sims (not just the big three) years and years ago.

Thanks Robert!  It's always great to have some objective feedback, and since you have a very good reputation with your Bonanza Turbo mod for MSFS, I would weight your feedback as more valuable than others.

There will probably be another Twitch Q&A in March, I think (if not March, then April). There is always a forum where we can post our questions for Microsoft/Asobo to answer in the Twitch Q&A, and have those questions upvoted, so Jorg/Seb/Martial will answer them.  For that next Twitch Q&A, if you could post your question and concerns, and how MSFS can improve the flight model further, and then let us know that your question has been posted so we can upvote it, that would be appreciated.  Then we can get your concerns in front of Microsoft/Asobo and at least get an answer from Jorg/Seb/Martial.  Cheers.

37 minutes ago, robert young said:

Another thing I do not quite understand: Asobo recently announced that it was going to start implementing accurate feathering of props, as though this was a mind-boggling, tremendous innovation. They backed this up with yet more claims of multiple dynamic lift and drag points all over the props with their array of green lines etc. But hang on. At Realair we implemented convincing prop feathering as far back as 2011 or thereabouts, and we didn't need over-complicated multiple prop lift points. We just overcame a few FSX and later P3D limitations and made it happen, as did quite a few other developers.

Thanks for your detailed thoughts Robert, good info.  Is it possible the multiple life/drag points might seem over-complicated (from a prop feathering perspective) given that it's meant to be a starting point to implement the coming helicopter/rotor support?

Any particular thoughts on the CFD stuff they showed? Seems pretty interesting (and not a trivial improvement) given the way surrounding air flow is modeled along with environmental winds and the interplay with all that and the aircraft body/surfaces & engines, vortices, etc. Not sure if more details have been provided to developers or in their developer forums and how 3rd party aircraft can start to take advantage of these enhancements.

What I consider revolutionary about MSFS is how it's brought together various tech stacks (cloud, AI, tapping into existing satellite/mapping systems to render the world, etc) to simulate a world and environment unlike any before, and IMHO it is in a completely different league altogether compared to other flight sims. Yes as you say the coming aerodynamics improvements are not necessarily revolutionary, but can only make the experience that much more complete, especially when aircraft are created to fully take advantage of what the core sim provides. That said, the computational fluid dynamics stuff is quite interesting, and would be great to get more details from both Asobo and 3rd party devs in the coming weeks.

Edited February 22, 20224 yr by lwt1971
spelling/grammar

1 hour ago, robert young said:

I'm afraid many make the mistake of assuming that just because certain parameters have been opened up or implemented by any core developer, that equals ALL flight models are going to be better. That is unfortunately not true.

This is why I said in my preceding post 'it is on the way', as in, it's not here yet, but the intention is clearly there to go in the right direction with this stuff. So whilst it's not necessarily there in complete form yet with all the parameters necessary to achieve instantly brilliant results with everything, I still take it as showing the desire for good intent as far as developing a good flight simulator is concerned.

Anyone who knows anything about XPlane's much-vaunted blade element flight modeling will know that, whilst many people claim this means you can make a 3D shape for the sim and have it behave like a real component of the same shape on a real aeroplane straight away, this isn't the case; such things generally need a bit of additional tweaking to get the behaviour right, so it's not really anything new to be aware that what MSFS currently has is by no means perfect either, especially given its young age, but this of course does not mean it won't be further tweaked to get nearer that goal with additional parameters to improve matters. 

The reason I mention this in XPlane, is that what we effectively have now, is two PC based flight sims which provide a spur for one another to improve this stuff.

Edited February 22, 20224 yr by Chock

20 minutes ago, Chock said:

Anyone who knows anything about XPlane's much-vaunted blade element flight modeling will know that, whilst many people claim this means you can make a 3D shape for the sim and have it behave like a real component of the same shape on a real aeroplane straight away, this isn't the case; such things generally need a bit of additional tweaking to get the behaviour right, 

Yes, I think this is the holy grail of a flight simulator.  If the flight model engine is sophisticated enough, the 3rd party developer merely needs to define the 3D shape of their plane, and how much thrust it can generate whether by propeller or by jet engine, and the flight model engine will do the rest.  By this definition, I think MSFS has a more accurate flight model engine than P3D, at least for 3rd party developers that don't want to tweak their flight model.

From what Robert Young has wrote, my overall interpretation is that FSX and P3D do not have as advanced a flight model engine; however, FSX and P3D allow more flexibility for the 3rd party dev to "tweak" the flight model of their specific plane, thereby yielding better results because of the flexibility to tweak.

But the holy grail of a flight model engine is that the 3rd part developer shouldn't need to tweak the flight model of their plane.  They should simply define the plane's 3D shape, the weights of the parts, the amount of forward thrust their plane can generate by propeller or by jet engine, and the flight simulator's flight model engine should be able to do all the rest, with little to no tweaking required by the 3rd party developer.

I suppose this is the holy grail of a flight simulator's flight model engine.  In essence, the holy grail of a flight simulator's flight model engine is to reproduce real world physics in the flight simulator.  As is real life, airplane manufacturers build and define the 3D shape of their planes, and mount the appropriate propeller(s) or jet engine(s) on their plane, but real world physics will determine how the plane flies.  There is no "tweaking" done by airplane manufacturers on their plane's flight model in the real world by some magical computer code.  In the real world, if plane manufacturers want to change the behavior of their plane, they need to change the 3D structure of it and/or change how the thrust is generated by the propeller(s) or jet engine(s).  I can see what MSFS is trying to achieve by making the flight model engine more advanced, so that it better simulates the physics of the real world.  Having said that, until the MSFS flight model gets that advanced, it wouldn't hurt to allow a some more flexibility for 3rd party devs to tweak their plane's flight models as a stop gap measure.

Edited February 22, 20224 yr by abrams_tank

I know next to nothing about the physics, but from a language pointe of view is it not common to distinguish between the simulator’s overall ‘aerodynamics model’, and an individual plane’s ‘flight model’? 
 

I try to follow the conversations as much as possible but sometimes it seems like people are using both terms interchangeably, and I’m wondering if I understand them correctly…?