The jump scare is a classic trope used in almost all horror films, but this trope has gone beyond the horror genre to crop up in other films, where it comes as even more of a surprise. Jump scares have become an integral part of horror films. Following a buildup of tension, a sudden jolt of action can reset the tone, relieve the tension, and serve as a way to reveal antagonists. Due to how effective they are for soliciting scares, and often a physical jump, as is characteristic of the name, they continue to be used frequently.

https://screenrant.com/best-jump-scares-non-horror-movies-ranked/