Capacity

Storage capacity of hard drive and expressed in Megabytes and Tetra bites and is lesser than specified by the manufacturers.

Cache

Cache is the buffer between the computer and hard drives

Compatibility

External hard drives compatibility with the computer and Operating system as indicated by the manufacturers

Disk Partitioning

Diving the hard drive to parts and making it available for an operating system. When we do multiple partitions on one drive, each partition appears as a individual drive to every OS.

Firewire

Method or interface to transfer data between the computer and the external hard drive and also referred as IEEE 1394 and is available in two versions

Form Factor

Forma factor of external hard drive defines the dimension of the hard drive (8-inch, 5.25-inch). Higher form factor offers better capacity and smaller ones better portability

FAT

File Allocation Table created by Microsoft and used for hard drives and high storage capacity external drives and FAT 32 is the latest version

Interface

Interface connects the computer to hard drive and determines the bandwidth of data transfer

Mbps

Stands for Megabits per second and 1 megabit is equal to 1000 kilobits

NTFS

Stands for new technology file system launched by Microsoft and supports hard drives with size up to 256 TB

Plug and Play

External hard drives easily recognized by computer, which eliminate the requirement of configuration.

Port

A connection slot in the computer, which aids in connecting external devices to the computer

RPM or Spindle Speed

Spindle speed of external 3.hard drive determines the performance

Rotational Speed

Spinning rate of the external hard drive, the faster the better is the transfer speed

Seek time

Time taken to read or write the data back and forth from the external hard drive

Sata (Serial AT Attachment)

Sata is the common interface used for peripherals and optical discs

SCSI

Stands for Small Computer System Interface, which is a parallel interface to connect peripheral devices used in Apple Macintosh computers

USB

Stands for universal serial bus and type of computer port