By Molly Vallance
a hard drive is a storge device used for storing and recieving digital information using disks that rotate very fast. they are coated wih a magnetic material. a HDD retains its data even when it has been turned off. the data is read in random access manor. The hard disk was first introduced on September 13,1956 and consists of one or more platters inside of an air-sealed casing. internal hard disks reside in a Drive bay and connect to the motherboard using an ATA, SCSI, or SATA cable, and are powered by a connection to the PSU (power supply unit). Below is a picture of what the inside of a hard drive looks like for a desktop and laptop hard drive.