Cursor Definition

A cursor is a small, movable marker that indicates the active position on a computer display screen.

The active position is the location at which the next character will be entered or some other activity will take place. Cursors are a crucial element of human-computer interfaces and play a key role in computer usability (i.e., the ease, comfort, efficiency and satisfaction with which a product can be used).

In the most basic of command line programs (i.e., all-text mode programs), the cursor takes the form of a solid rectangle or an underline, often blinking. It will move automatically to the right as text is typed in or to the left as text is deleted. It can also be moved with some keys, including the arrow keys.

On more sophisticated command line programs for which a mouse is supported, there will be two cursors. One is the marker that automatically signifies the active position. The other is the mouse cursor, also referred to as the mouse pointer, which is used to move the other cursor or to select sections of text for simple editing such as copying.

When working in a GUI (graphical user interface), the image used for the mouse cursor in most application programs will change to show the user the type of action that is currently being performed or that can be performed at a particular location on the screen. The default image for a GUI cursor is usually a small arrow pointing upward and slightly to the left (an 11 o'clock position).

The default shape for GUI cursors when over text is an I-beam (i.e., a vertical bar with short crossbars at the top and bottom), because this shape makes it easy to select sections of text for copying, deletion, etc. When this cursor moves over a hyperlink, it changes to a hand with an outstretched index finger to provide an immediate indication that it is a link and to show that the link points to some other location (i.e., on the same page or some other page).

Other commonly used cursor images include a magnifying glass to enlarge graphic images, a hand with all fingers extended to indicate that an icon or other item is being dragged by the mouse, a double arrow (which can have a horizontal, vertical or diagonal orientation) to show that the edge of a window or frame can be adjusted in the indicated direction, and an hourglass or wristwatch to indicate that a program is currently performing some task and is currently unable to accept user input.

The types and variety of cursors used can vary considerably according to the program. They are particularly plentiful in graphics programs, such as the GIMP, for which there are different cursors for each of the more than two dozen basic tools.

The term cursor was used in other products prior to the development of computer displays, including typewriters and slide rules. It comes from the Latin word cursus meaning runner and is related to the word course.

Created May 19, 2006.
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