Computers Chapters 8

Storage device

the hardware that records and/or retrieves items to and from storage media

Writing

the process of transferring data, instructions, and information from memory to a storage medium

Reading

the process of transferring these items from a storage medium into memory

Capacity

the number of bytes (characters) a storage medium can hold

Secondary storage

the physical material on which a computer keeps data, information, programs, and applications

internal hard drive

sometimes used to refer collectively to hard disks and SSDs inside a computer

external hard drive

may be used to refer globally to external hard disks and external SSDs

Access time

measure the amount of time it takes a storage device to locate an item on a storage medium or the time required to deliver an item from memory to the processor

Transfer rate

the speed with which data, instructions, and information transfer to and from a device

Hard disk

a storage device that contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information

platter

made of aluminum, glass, or ceramic and has a thin coating of alloy material that allows items to be recorded magnetically on its surface

Longitudinal recording

aligns the magnetic particles horizontally around the surface of the disk

perpendicular recoding

hard disks align the magnetic particles vertically, or perpendicular to the disk's surface, making much greater storage capacities possible

density

the number of bits in an area on a storage medium

Formatting

the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk

track

a narrow recording band that forms a full circle on the surface of the disk

read/write head

the mechanism that reads items and writes items in the drive as it barely touches the disk's recording surface

disk cache

sometimes called a buffer, consists of a memory chip on a hard disk that stores frequently accessed data, instructions, and information

RAID

a group of two or more integrated hard disks

external hard disk

a separate freestanding storage device that connects with a cable to a USB port or other port on a computer or mobile device

solid-state media

they consist entirely of electronic components, such as integrated circuits, and contain no moving parts

SSD

a flash memory storage device that contains its own processor to manage its storage

memory card

a removable flash memory storage device, usually no bigger than 1.5 inches in height or width, that you insert in and remove from a slot in a computer, mobile device, or card reader/writer

USB flash drive

sometimes called a thumb drive, is a flash memory storage device that plugs in a USB port on a computer or mobile device

cloud storage

is an internet service that provides storage to computer or mobile device users

optical disc

a type of storage medium that consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser

full backup

provides the best protection against data loss because it copies all program and data files

differential backup

copies only the files that have changed since the last full or last incremental backup

selective backup

allows the user to choose specific files to back up, regardless of whether or not the files have changed since the last incremental backup

backup software

enables you to schedule backups, select the appropriate backup type, and choose the storage media for the backup

fibre channel

technology as the interface that connects the devices to the network because it has much faster transmission rates than SCSI and other previously discussed interfaces

mirroring

writes data on two disks at the same time to duplicate the data

striping

splits data, instructions, and information across multiple disks in the array

network attached storage

a server that is placed on a network with the sole purpose of providing storage to users, computers, and devices attached to the network

storage area network

a high-speed network with the sole purpose of providing storage to other attached servers

tape

a magnetically coated ribbon of plastic that is capable of storing large amounts of data and information at a low cost

tape drive

reads from and writes on a magnetic tape

tape cartridge

a small, rectangular, plastic housing for tape

tape library

where individual tape cartridges are mounted in a separate cabinet

magnetic stripe card

a credit card, entertainment card, bank card, or other similar card with a stripe that contains information identifying you and the card

smart card

an alternative to a magnetic stripe card, stores data on an integrated circuit embedded in the card

RFID tag

consists of an antenna and a memory chip that contains the information to be transmitted via radio waves

microfilm

a 100- to 215-foot roll of film

microfiche

a small sheet of film, usually about 4 x 6 inches

computer output microfilm recorder

the device that records the images on the film