Description

Sets the stacking order of positioned elements.
Higher numbers are rendered on top or closer to the user.
So called after the depth dimension axis 'z'; as in x, y and z.

Example

 #ontop{
  position absolute; top:0; left:0; z-index:5;
}
#below{
  position:absolute; top:0; left:0; z-index:1;
}

Values
integer or auto
Default value
auto
Introduced in CSS version
2.1
Applies to elements
Positioned elements
Inherited
No
Browser Support
BrowsersIE ieFirefox firefoxSafari safariOpera operaChrome chrome
Versionsfull 8, part 51160.2
Belongs to:

See the full list CSS properties and browser support: CSS Properties