Basically what @Raildex_ said. If you are moving your character (say a vehicle) by using a specific value (say Float of 20 every Tick). You want to use the node “Get World Delta Time” and multiply this value to your movement value. This will apply the same movement delta per tick (frame) no matter your actual framerate.
If you are using the default Character BP that comes with the Thirdperson template then you dont have to do this.