What is the process of preparing a disk for reading or writing called?

The process of preparing a disk for reading or writing is called formatting. Formatting a disk involves creating a file system on the disk that allows the operating system to read and write data to the disk. There are different file systems supported by different operating systems. Common file systems include NTFS for Windows, FAT32 for older versions of Windows and some older devices, and EXT4 for Linux. When you format a disk, the existing data on the disk is usually erased. Therefore, it's important to back up any files you want to keep before formatting a disk.