TP, or Return to Player, refers to the measure of the percentage of stakes that is returned to the player (through wins).
Usually, when we talk about the RTP of a game, we refer to the theoretical RTP: the average win over many game rounds divided by the bet.
Most NetEnt games have a theoretical RTP of approximately 96%.
But any time you sit down to play, there is an actual RTP: the total win of the session divided by the total bet of the session. For a short play session, this can be very far from the theoretical RTP value. For example, say you sit down and play with 100 euro, and in the end you leave the session with 70 euros – your actual RTP, in this case, is 70%. The important thing to remember when you see the listed RTP of a game is that this is the average RTP after a very long run of games, and is the not to be taken as the actual RTP.