The keyboard shortcut "Ctrl+Z" is commonly used in computer applications to undo the last action performed. This function is helpful when a mistake is made, allowing users to revert changes quickly without needing to manually correct them. It is widely supported across various software, including word processors, graphic design tools, and coding environments. When using "Ctrl+Z," the action can often be repeated multiple times to undo several previous actions in succession. This feature enhances productivity and reduces frustration, making it easier for users to experiment and make changes without fear of permanent errors.