A status bar, similar to a status line, is an information area typically found at the bottom of window

Window (computing)

In computing, a window is a visual area containing some kind of user interface. It usually has a rectangular shape that can overlap with the area of other windows...

s in 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...

.
A status bar is sometimes divided into sections, each of which shows different information. Its job is primarily to display information about the current state of its window, although some status bars have extra functionality. For example, many web browser

Web browser

A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

s have clickable sections that pop up a display of security or privacy information.

A status bar can also be text-based, primarily in console-based applications, in which case it is usually the last row in an 80x25 text mode

Text mode

Text mode is a kind of computer display mode in which the content of the screen is internally represented in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of character cells, each of which contains one of the characters of a...

 configuration, leaving the top 24 rows for application data. Usually, the status bar, typically called a status line in this context, displays the current state of the application, plus helpful keyboard shortcut

Keyboard shortcut

In computing, a keyboard shortcut is a finite set of one or more keys that invoke a software or operating system operation when triggered by the user. A meaning of term "keyboard shortcut" can vary depending on software manufacturer...

s, such as in the 'vi' text editor of UNIX (from the 1970s) or newer Linux systems.

Status lines have been used for more than 30 years to display advisory messages in a predefined area, rather than as pop-up messages in center screen which can block the view of related information behind the pop-up messages. Although pop-up windows could be used to focus attention, status lines with contrasting hightlighting or colors can also be used to focus attention, without blocking the view.

Sometimes, a video game places the player's vital information (such as hit points, lives, and score) on a similar strip across the bottom or top of the screen; this is also referred to as a status bar.

A status bar can be implemented during software development as a component (widget

Widget (computing)

In computer programming, a widget is an element of a graphical user interface that displays an information arrangement changeable by the user, such as a window or a text box. The defining characteristic of a widget is to provide a single interaction point for the direct manipulation of a given...

) in a window

Window (computing)

In computing, a window is a visual area containing some kind of user interface. It usually has a rectangular shape that can overlap with the area of other windows...

 in 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...

.

Examples

• The status bar of a file manager
  File manager
  A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, view, print, play, rename, move, copy, delete, search/find, and modify file attributes, properties...
  
   often shows the count of items in the current directory, their total size, or the size of the currently selected item.

• The status bar of a web browser
  Web browser
  A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
  
   will sit relatively dormant when the user is viewing on a page, then light up with a flourish of activity when the user clicks a link.
• The status bar of a graphics editor will show information about the current image, such as its dimensions, colour space, or resolution
  Image resolution
  Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....
  
  .
• In a word processor
  Word processor
  A word processor is a computer application used for the production of any sort of printable material....
  
  , the status bar often shows cursor position, the number of pages in the document, and the state of the caps lock
  Caps lock
  Caps lock is a key on many computer keyboards. Pressing it sets an input mode in which typed letters are uppercase by default. The keyboard remains in caps lock mode until the key is pressed again...
  
  , num lock
  Num lock
  Num Lock is a key on the numeric keypad of most computer keyboards. It is a toggle key, like Caps Lock and Scroll Lock. Its state is commonly represented by an LED light built into the keyboard....
  
  , and scroll lock
  Scroll lock
  Scroll lock is a keyboard button on some computer keyboards. The key is not frequently used and therefore some keyboards lack Scroll Lock altogether....
  
   keys. Additionally, many word processors assign the insert key a behaviour similar to that of these three, to allow toggling the insertion mode the state of that is also displayed in the status bar.
• In a spreadsheet
  Spreadsheet
  A spreadsheet is a computer application that simulates a paper accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. Each cell contains alphanumeric text, numeric values or formulas...
  
  , the status bar shows similar information to word processors, but includes the ability to highlight cells and show the average, sum, maximum value, and so forth.

Status bars allow split-window interface

Status bars, and status lines before them, have been used for years to display advisory messages in a predefined area, rather than as pop-up messages in center screen which can block the view of related information behind the pop-up messages. The use of status bars (or status lines) involves both advantages and disadvantages:

Advantages of status bars:

• status bars allow viewing messages while viewing the total screen;
• status bars allow typing information while viewing status data;
• status bars allow other menu options while viewing status data;
• status bars can continually show status during operation.

Disadvantages of status bars:

• status bars might restrict information to a one-line display (although a variable multi-line status bar/region could be used);
• status bars typically cannot pop to the surface for critical messages.

Although pop-up windows could be used to focus attention, status lines with contrasting hightlighting or colors can also be used to focus attention, without blocking the view.