I'm a bit confused since I've seen it often in this site.

What's actually the real meaning of au/alternate universe?

What's the difference between au and semi-au?

And...why is it some of the authors put a tag to their stories as 'au'? Example; highschoolau

Am i the only who doesn't know about this? Shame on me. T_T 

P/s: got7 was in vancouver yesterday. who got the chance to meet my 'boyfriends' for real??? T______T