Mouse Hover
Many interactive elements on the web require the user to hover the mouse over a page element – drop-down or fly-out menus, tooltips, etc. Mouse hover functionality is usually not accessible to keyboard-only users (note that the functionality can sometimes be programmed to respond to keyboard focus or pressing Enter in addition to mouse hover). Perhaps more significant, hover functionality is not generally available on touch screen devices where only tap/click events are recognized. Because of these compatibility and accessibility issues, functionality should be programmed to not rely on mouse hover interactions.
