Difference
The mouseenter and mouseover events are triggered when you move the mouse over an element.
mouseenter only triggers when the mouse enters the element on which it is set. The counterpart event is mouseleave.
mouseover triggers when the mouse enters the element or any of its children. Its counterpart is mouseout.
Good practice
Because the mouseover event propagates from the child element up through the hierarchy, if you're doing a resource-intensive task on the event you may notice the screen flickering.
It's recommended to use the mouseenter and mouseleave events instead.