symbols after game titles on roms - Game Gear emulation

[Dann-Oh]

I'm new to emulation and roms so pardon this question if it is basic and silly so here it goes. What are the different symbols after the game roms in the title line. Do they have a significance? see the below for an example of what Im talking about. After I extract the files from their compressed folder I would have expected to see a game rom, Aerial Assault, instead I see multiple rom files. I have seen on other games where there are nearly 25 different options of the rom. If I a looking for the original (unadulterated) rom I would think I would want the "Aerial Assault (JU) (V1.0).gg" file what does the "(JU)", "(v1.0)", and the [b1]/[!] mean? these are all new to me.

Files after extraction:
Aerial Assault (JU) (V1.0) [b1].gg
Aerial Assault (JU) (V1.0).gg
Aerial Assault (JU) (V1.1) [!].gg

[Zorlon]

(JU) (Japan/USA Release) (Plenty use this) [You can also get JUE and JE & UE as well as the standard J, U & E though not just targeting GameGear there]
[b#] = Verified Bad Dump (Good Tools naming) there can be many bad dumps hence the number included
[!] Verified Good Dump (Good Tools naming) [The ones with nothing after the regional code are considered good dumps or at least the best available just not verified good yet]
(V#.#) Version information (Plenty use this and it is just used when a game has an official re-release with some roms changes usually just bug fixes, occasionally copy protection add, though can't see copy protection ever being added to GameGear games so for those chances are it was a bug fix)

For a full list check out Download Links:
Links are hidden from guests. Please register to be able to view these links. If you don't want all the junk then go for a No-Intro set for roms

There are tons of rom sets out there

Good Tools :- These have everything in them the good the bad the hacked and even homebrew
Tosec :- These are mostly for older computer type systems but also include some consoles, a bit more organized that Good Tools, but do still have hacked/cracked games
No-Intro :- Mostly direct cart dumps, so no hacks or cracks
Trurip :- These are mostly CD systems and up and is a build on Tosec
Redump :- These are mostly CD systems and are raw dumps of the original media (Not all the systems are complete) great for PSX not great for Dreamcast but comes in handy as a fill in for what has not been dumped into other sets, so occasionally it is a good idea to mix sets up a bit to get a fuller collection, 90% of the time it is not a good idea though

Arcade sets are based on what the emulator can play rather than just full sets from a single system and are aimed directly at each emulator so although two different Arcade emulators may support some of the same games, but it does not go that a rom from one arcade system will work on the other even if it is a game both support as they may use different rom dumps

I have possibly missed some but it is just to give you an idea of what sets are out there