Throbber

A throbber, also known as a loading icon, is an animated graphical control element used to show that a computer program is performing an action in the background (such as downloading content, conducting intensive calculations or communicating with an external device).

[4] The IBM WebExplorer offered a webpage the opportunity to change the look and the animation of the throbber by using proprietary HTML code.

In text user interfaces and command lines, the spinning wheel is commonly replaced by a fixed-width character which is cycled through discrete states, such as "|", "/", "-" and "\", which act as the frames of a looping animation-like effect.

Unlike graphical activity indicators, this style of throbber is commonly paired with a progress display like a bar, since the lower effective resolution of character-based progress bars can benefit from a separate indication of activity.

This style of throbber dates from versions of UNIX appearing in the latter 1970s, and DR-DOS utilities in the 1980s, since it requires at least a character-cell addressable display—i.e.