A progress indicator is an element of a command line interface, a textual user interface

Text user interface

TUI short for: Text User Interface or Textual User Interface , is a retronym that was coined sometime after the invention of graphical user interfaces, to distinguish them from text-based user interfaces...

, or a graphical user interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 that is intended to inform the user that an operation is in progress, to reassure that the system is not hung or waiting for user input,
and often to provide the user with an estimate of how far through a task the system has progressed.

Examples of progress indicators

• The progress bar
  Progress bar
  A progress bar is a component in a graphical user interface used to convey the progress of a task, such as a download or file transfer. Often, the graphic is accompanied by a textual representation of the progress in a percent format....
  
  .
• The throbber
  Throbber
  A throbber is a graphic found in a graphical user interface of a computer program that animates to show the user that the program is performing an action .-Typical characteristics:...
  
  .
• The splash screen
  Splash screen
  A splash screen is an image that appears while a game or program is loading. It may also be used to describe an introduction page on a website. Splash screens sometimes do not cover the entire screen, but only a rectangle near the center...
  
  .
• The hourglass mouse cursor.
• The spinning wait cursor
  Spinning wait cursor
  The spinning wait cursor is a cursor in Apple's Mac OS X that indicates an application is not responding to system events.The Apple Human Interface Guidelines officially refers to it as the "spinning wait cursor"...
  
  .
• The startup window for KDE
  KDE
  KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...
  
   is a graphical user interface progress indicator, with the icons along the bottom of the window changing appearance as each part of the startup procedure is executed.
• The textual user interface versions of the PKZIP
  PKZIP
  PKZIP is an archiving tool originally written by Phil Katz and marketed by his company PKWARE, Inc. The common "PK" prefix used in both PKZIP and PKWARE stands for "Phil Katz".-History:...
  
   and RAR utilities display a running percentage as individual files are compressed.

Further reading

— the Apple

Apple Computer

Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

 Human Interface Guidelines for progress indicators — how to create a progress indicator in the status bar of an application using MFC