"Control + A" is a keyboard shortcut commonly used in computer applications to select all text or items within a document or window. This command is helpful for quickly highlighting everything, allowing users to copy, cut, or format the selected content efficiently. It works in various software, including word processors like Microsoft Word and web browsers. When you press "Control + A," the entire content becomes highlighted, making it easy to perform actions on all selected items at once. This shortcut is available on most operating systems, including Windows and Linux, while the equivalent on Mac systems is "Command + A."