The keyboard shortcut "Command + S" is commonly used in various software applications to save a document or file. This command is particularly useful for preventing data loss, as it allows users to quickly save their work without navigating through menus. It is available on devices running the macOS operating system. When you press "Command + S," the application saves the current state of your work, whether it's a text document, image, or project file. This shortcut is a standard feature in many programs, including Microsoft Word, Adobe Photoshop, and Apple Pages, making it an essential tool for efficient workflow.