When you roll the cursor over a link on a Web page, it is often referred to as "hovering" over the link. This is somewhat like when your boss hovers over you at work, but not nearly as uncomfortable. In most cases, the cursor will change from a pointer to a small hand when it is hovering over a link. Web developers can also use cascading style sheets (CSS) to modify the color and style of link when a user hovers over it. For example, the link may become underlined or change color while the cursor is hovering over it.
The term hovering implies your computer screen is a three-dimensional space. In this conception, your cursor moves around on a layer above the text and images. When you click the mouse button while the cursor is hovering over a link, it presses down on the link to activate it. Hovering can also be used in a more general sense such as moving the cursor over icons, windows, or other objects on the screen.