mousewheel control

A scroll wheel (or mouse wheel) is a hard plastic or rubbery disc (the “wheel”) on a computer mouse that is perpendicular to the mouse surface.

Computer windows are often not large enough to display the entire contents of the window at one time. Therefore, you may need to scroll through the window to view all the contents.

Traditionally, this has been done by clicking and dragging the slider within the scroll bar. However, many mice now come with mouse wheels that make the scrolling process even easier.

The mouse wheel typically sits between the left and right buttons on the top of a mouse. It is raised slightly, which allows the user to easily drag the wheel up or down using the index finger. Pulling the mouse wheel towards you scrolls down the window, while pushing it away scrolls up.

Most modern mice include a scroll wheel, since it eliminates the need to move the cursor to the scroll bar in order to scroll through the window.