RTP is a long-run average; house edge is the casino’s expected share: 96% RTP =...

https://blogfreely.net/teresa-long85/whats-a-risk-preference-choice-when-picking-casino-games

RTP is a long-run average; house edge is the casino’s expected share: 96% RTP = 4% house edge. Volatility describes how uneven wins can be. In a short session, results can swing sharply, so you may lose more—or win more—than the averages suggest.