RTP stands for Return to Player. It is a term that describes the percentage of bets that a pokie returns to players as winnings over time. If several players collectively bet $100 on a slot with an RTP of 96%, it means that $96 will be distributed as wins to across the entire player network.
In other words, you will not win 96% of your spins when you play a pokie with an RTP of 96%. RTP percentages are measured over a vast number of spins.