CheatingCheating is any kind of treacherous or unfair manipulation of the game. In poker, it might be done by fixing the cards, making agreements with other players, hiding cards, stealing chips, etc. In the context of online games, collusion and pokerbots (programs that play poker), as well as global databases of player data are the main forms of cheating. Different platforms have different views on data mining, which is the automated observation of players for the purpose of gathering statistics on them, to be later used in programs like Pokertracker or Pokeroffice.
Online poker platforms go to great pains to curb cheating by looking for suspicous patterns in a client's played hands. They also check for banned processes running on the client's machine.