Well if you haven't played Fashion Business yet then,
1) EP 1 is the first episode
2) EP
2.1 v0.16 is the second episode
3) EP 2.2 v3 is the
continuation of EP 2.1 v0.16(basically the same episode but as the game got bigger the dev thought to make it a separate one)
They all are separate files(cause the game will be too big in just one file) and yeah they do not include the same content, but the choices you make in each one is connected.
So if you are starting just go for EP 1 (its the beginning and you get to know the story a bit), then EP 2 and then the newest version which is EP 2 v3.
You can get away with playing either one right off the bat but it will be no fun cause you won't get the feel of it.
Good luck as the game is kinda grindy so better use a walkthrough