:facepalm: I looked at that already, it didn't help, so try again
Basically it's used to organise matches, both casual and pro. there's 6v6 and 9v9, with the option of having highlander turned ON (Which limits 1 player per class) It's commonly used for clan matches but you can login and join any open match you want. There's EU, US and Russian lobbies for your preference. You can also start a match if you have a server with the tf2lobby plugin.
 
Basically it's used to organise matches, both casual and pro. there's 6v6 and 9v9, with the option of having highlander turned ON (Which limits 1 player per class) It's commonly used for clan matches but you can login and join any open match you want. There's EU, US and Russian lobbies for your preference. You can also start a match if you have a server with the tf2lobby plugin.
Thanks, this really helped
 
Just to clarify. TF2 Lobby is a way to organise PUGs (pick up games) using a competitive format.

TF2 Lobby is a way for competitive players to just relax and have fun without the clusterfuck of pubs like 32player 24/7 Dustbowl. Newer players tend to use TF2Lobby to experiance the competitive format.

IMO lobby is not great and a 6v6 newbie mix is a better way for newer players to understand the format as recieve training from experianced players who won't get mad at you for doing something wrong.

However,if you want to play Highlander, Lobby is a fairly good way to be introduced to it.

Hoped this helped.
 
Also, lobbies tend to have less noobs, so if you want to play with people taking the game more seriously it's better than pub games.