Jquery z-index explained
The z-index property determines the stack level of an HTML element. The “stack level” refers to the element’s position on the Z axis (as opposed to the X axis or Y axis). A higher value means the element will be closer to the top of the stacking order. This stacking order runs perpendicular to the display, or viewport. Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, PHP, Python, Bootstrap, Java and XML.