Definition of OTB
OTB means "on the button" (on the button). Being OTB, gives us a huge advantage over our opponents since we will have a maximum of information. preflop, if no one has made a raise, player OTB is in a good position to steal the blinds. If we have an interesting but not exceptional hand, we can have a good preview of the preflop action. For example, a player who has 77 in UTG position will raise to 3 big blindss. If both players after him 3bet and 4 bet, he will be forced to fold and he will lose 3 big blinds. If this player had been on the button, he would have just folded his hand.
OTP, an advantage preflop and postflop
postflop (after the flop), player OTB will also be the last one to speak out of all streets. So he will be in an excellent position to bluff if all the players are checked, he will be able to make big folds if there is too much action before him, he will be able to make good betss on the river. The beauty with the strength of the position is that even if you don't really understand its advantages, automatically you will have better performance in position than out of position. Position is a magic that works even on those who are not aware of it.