SATA / Serial ATA Hard Drives come in two basic types - Enterprise grade and desktop grade. Enterprise grade SATA disks are built for 24x7 operation and are almost exclusively used in servers that use hot swappable (hot-swap) drives with a SAS or SATA hot pluggable backplane. You use a hard drive tray or caddy or sled, and simply slide and clip the drive into the front of your server. Desktop grade drives, as the name implies, are mostly used in less intense desktop applications.