Z-Index is a CSS property that controls the stacking order or depth of an element within a web page's layout. It determines which elements appear in front of or behind other elements on the same webpage. Elements with higher Z-Index values appear in front of elements with lower values.
Z-Index is often used to manage the layering of elements in web design, such as positioning pop-up windows, dropdown menus, or elements with overlapping content. It is especially useful in creating complex and interactive user interfaces.
Careful use of Z-Index ensures that web elements are displayed as intended in the visual hierarchy of a webpage.