RTP is the share a game is designed to return over many plays: 96% RTP means a...

https://telegra.ph/Is-There-Any-Point-Comparing-RTP-if-All-Games-Are-Negative-EV-11-05

RTP is the share a game is designed to return over many plays: 96% RTP means a 4% house edge. Volatility affects how wins and losses arrive. In a short session, results can differ sharply from the long-run average.