CTF stand for "Capture the flag". It's a simulate hacking by give each team(player) can hack another team(player) then when you hacked another you will get score.
My impression about CTP competition is me and my team go to CTF competition at "CDIC 2014" event.This is my first CTF competition but my team can make a good score. In CDIC 2014 event except competition then we meet another who Interested in computer security.