What is the purpose of the z-index and how is it used?

The z-index is a CSS property that controls the vertical stacking order of HTML elements that overlap each other on a web page. The z-index property is used to determine which element should appear on top of other elements, and it is commonly used to position elements in a specific order on a webpage.

The z-index property accepts a numeric value, which determines the position of an element in the stacking order. Elements with a higher z-index value will appear on top of elements with a lower z-index value. If two elements have the same z-index value, the element that appears later in the HTML source code will appear on. top