Double-Click
A double-click is two clicks of a mouse button in quick succession, typically within half a second. Operating systems recognize the action as a single, distinct command rather than two separate clicks.
A double-click can perform several different actions within a graphical user interface, but it is most commonly used to open an item. For example, you can double-click an icon to open the associated file, folder, or application. Double-clicking within an application may produce other actions. For instance, if you double-click a word in a text document, the word processor will select the entire word.
Double-Clicking in the Age of Touchscreens
While double-clicking remains a core part of desktop computing, its relevance has diminished somewhat with the rise of touchscreen interfaces (where single taps and long presses have replaced the action). Because so many people now use mobile devices, modern applications and websites are often designed to respond to single clicks or taps for simplicity and accessibility.
NOTE: The terms "double-clicking" and "double-tapping" may be used interchangeably when referring to a touchscreen interface.