Choosing a startup disk on a Mac computer refers to selecting the specific storage device or volume from which the operating system will load and run when the computer starts up. The startup disk contains the necessary files and data required for the computer to boot up and function properly.
Selecting the correct startup disk is important for ensuring a smooth and successful boot process. If the wrong disk is chosen, the computer may fail to start up or may experience errors. Additionally, having multiple startup disks can be useful for troubleshooting purposes, testing different operating systems, or accessing specific files or data.