Hard disks

The hard disk is the computer's body, which store data permanently, unlike the RAM, which is erased each time you restart the computer, this is why it is sometimes called memory mass to designate hard drives. The hard disk is connected to the motherboard via a hard disk controller that interfaces the processor and the hard disk. The hard disk controller manages the disks attached to it, interprets the commands sent by the processor and routes them to the disk concerned. The following interfaces are generally distinguished:

• IDE
• SCSI
• Serial ATA

With the advent of USB, external enclosures for connecting a hard drive to a USB port have appeared, making the hard drive easy to install and to add more storage capacity for backups. This is referred to as an external hard drive as opposed to internal hard drives plugged directly to the motherboard, but these are the same drives, except that they are connected to the computer via a box plugged into a USB port.