Tab arrow mark1. Usually about five spaces wide, a tab is an indentation at the beginning of a line of text to signify a new paragraph in a document or to help create equal spacing between multiple lines. When formatting marks are visible, tabs are represented by an arrow, as shown in the example picture to the right.

Tab in a regular expression

With many programming languages and when working with a regular expression, a tab is matched by using the "\t" meta-character or escape sequence. For example, with the Perl code below if the $example variable contains any tab, the script would print "I found a tab!" when ran.

if ($example =~ /\s/) { print "I found white space!"; }

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2. In an Internet browser, a tab refers to an open web page in tabbed browsing. See our tabbed browsing definition for a full explanation, examples, and pictures for this term.

3. In a software program window and in an Internet browser, a tab allows for the user to access different parts of a menu, program window, or web page. Below is an example of what tabs may look like in a Microsoft Windows setting.


Tip: Use the keyboard shortcut Ctrl + Tab to switch left-to-right between open tabs in a document or web browser. To move back or right-to-left use the keyboard shortcut Ctrl + Shift + Tab.

Tab keyboard key4.Tab is a key (shown right) located on the far left side of nearly all computer keyboards that has many uses. For example, in a word processor, they tab key may be used to insert a tab character or advance the typing cursor to the right by five characters. This key can also move between selectable items in a dialog box, or switch between tabs in an Internet browser.

Where is the tab key on the keyboard?

Below is an overview of a computer keyboard with the tab key highlighted in blue.

Tab key

Why is there a forward and backward arrow on Tab?

The tab key is capable of moving forwards and backwards, although most people only use it to go forwards, which explains the right arrow. The left arrow is on the key because if you press Shift key and Tab at the same time the tab is moved backwards.

For example, you can press Alt + Tab to switch between open windows in Microsoft Windows and other operating systems and pressing Alt + Shift + Tab moves backwards. The same is true with open tabs as mentioned earlier on this page. As far as word processors and other programs dealing with text, pressing Shift + Tab decreases the indent in most programs. With early versions of Microsoft Word you may have to press Ctrl + Shift + M.

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5. A tab is a plastic piece used to enable/disable write-protection on floppy diskette drives.

6. When referring to a command, tabs is a Linux command that sets tabs in the terminal. See the tabs command for further information.

7. A tab is sometimes used as an abbreviation of tablet.

Also see: Floppy drive definitions, Indent, Keyboard, Keyboard terms, Operating system terms, Tab stop, White space