The levers (or buttons) on your 6EXA below and to the side of the sticks are your digital trims. My older 6XAs has analog trims where a wheel rotates to the right/left or up/down to adjust the control surface (in flight) then it stays there. The digital trims on the 6EXA always return to center when you nudge them to "blip" in small amounts of trim.

The advantage of digital trims is they can't accidentally be knocked off their last setting. The advantage of analog trims is you can quickly move the lever a bunch. Makes it handy to use the analog trim on your idle to cut off the engine - the throttle trim doesn't have any affect on the high side. On the 6XAs, you may not remember where the trim lever is supposed to be when you have multiple models in memory - each with their different trim settings. The 6XAs has a trim memory where after you have your airplane trimmed out (and the levers all over the place), hit trim memory which memorizes those trim settings for that model memory. Then you move your trim levers back to neutral. The control surfaces are still trimmed where you last trimmed it but you start again with a trim lever in it's center detent. Then if a trim lever gets "bumped" accidentally it's easy to find where it should be by moving the trim lever back to it's neutral setting where you can feel the center detent.

So to summarize,
The obsolete 6XAs has analog trims, subtrims (STRM) and trim memory (TMEM) which you have to set manually.
The current 6EXAs has digital trims but no subtrims. Digital trims get memorized automatically.
The 9CAPs I have has digital trims, subtrims and automatic trim memory.