Z-Index
The order that transparent layers of a Web page are stacked one upon another.
The layer with the highest z-index lies on top. This allows Web site designers to create various image effects by controlling the transparency of the layers.

Z-Index
The order that transparent layers of a Web page are stacked one upon another.
The layer with the highest z-index lies on top. This allows Web site designers to create various image effects by controlling the transparency of the layers.