Secondary Storage

FILE COMPRESSION

File compression is commonly used when sending a file from one computer to another over a connection that has limited bandwidth. The compression basically makes the file smaller and, therefore, the sending of the file is faster. Of course, when compressing a file and sending it to another computer that computer has to have a program that will decompress the file so it can be returned to "normal" and used.

HEAD CRASH

A serious disk drive malfunction. A head crash usually means that the head has scratched or burned the disk. If the head becomes misaligned or if dust particles come between it and the disk, it can touch the disk. When this happens, you usually lose much of the data on the hard disk and will need to replace both the head and the disk

INTERNET HARD DRIVE

The sole purpose of an Internet hard drive is to offer a means of accessing your computer files from any computer, as long as that computer has access to the Internet. Similar to depositing money into your bank account, and later withdrawing that same money from any ATM machine, an Internet hard drive will allow you to "deposit" your computer files into a remote hard drive, and then later access those very same files from any other computer.

OPTICAL DISC DRIVE

In computing, an optical disc drive (ODD) is a disk drive that uses laser light or electromagnetic waves near the light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from discs, but recent drives are commonly both readers and recorders. Recorders are sometimes called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives.

SOLID-STATE STORAGE

Solid-state storage is a nonvolatile, removable storage medium that employs integrated circuits (ICs) rather than magnetic or optical media. It is the equivalent of large-capacity, nonvolatile memory. Examples include flash memory Universal Serial Bus (USB) devices and various proprietary removable packages intended to replace external hard drives.

Input and Output

ERGONOMIC KEYBOARD

Ergonomic keyboard mainly solve the problems related to wrist ulnar deviation (hand deformity, seen in chronic rheumatoid arthritis and lupus erythematosus, in which the swelling of the metacarpophalangeal joints causes the fingers to become displaced to the ulnar side.

INK-JET PRINTER

A type of printer that works by spraying ionized ink at a sheet of paper. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes. Ink-jet printers are capable of producing high quality print approaching that produced by laser printers. A typical ink-jet printer provides a resolution of 300 dots per inch, although some newer models offer higher resolutions.

LASER PRINTER
A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. This is also the way copy machines work.

MAGNETIC-INK CHARACTER RECOGNITION (MICR)

MICR font is commonly used to print checks, deposit slips, mortgage coupons, etc. There are several MICR fonts, the MICR E-13B font is used in the Canada, Panama, Puerto Rico, UK, and the United States. The MICR CRC-7 was created according to the ISO standards and is a font used in France, Mexico, Spain, and most other Spanish speaking countries.

OPTICAL-CHARACTER RECOGNITION (OCR)

Often abbreviated OCR, optical character recognition refers to the branch of computer science that involves reading text from paper and translating the images into a form that the computer can manipulate. An OCR system enables you to take a book or a magazine article, feed it directly into an electronic computer file, and then edit the file using a word processor.

OPTICAL-MARK RECOGNITION

Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields, such as checkboxes and fill-in fields, on printed forms. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards, questionnaires and ballots.

The System Unit

FLASH MEMORY

Flash memory is a type of constantly-powered nonvolatile memory that can be erased and reprogrammed in units of memory called blocks. It is a variation of electrically erasable programmable read-only memory which, unlike flash memory, is erased and rewritten at the byte level, which is slower than flash memory updating

GRAPHIC CARDS

A graphic card is a piece of hardware installed in a computer that is responsible for rendering the image on the computer’s monitor or display screen. Graphics cards help take the processing strain off the main processor, and can contain their own memory to take the strain off the system RAM.

SOUND CARDS

An expansion board that enables a computer to manipulate and output sounds. Sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.

NETWORK INTERFACE CARD (NIC)

A network interface card, more commonly referred to as a NIC, is a device that allows computers to be joined together in a LAN, or local area network. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes. 

PLUG AND PLAY

Plug and Play is a capability developed by Microsoft for its Windows 95 and later operating systems that gives users the ability to plug a device into a computer and have the computer recognize that the device is there. In many earlier computer systems, the user was required to explicitly tell the operating system when a new device had been added. 

BUS LINE

In computer architecture, a bus is a subsystem that transfers data between computer components inside a computer or between computers. Early computer buses were literally parallel electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus. 


HDMI

HDMI is an interface standard used for audiovisual equipment such as high-definition television and home theater systems. With 19 wires wrapped in a single cable that resembles a USB wire, HDMI is able to carry a bandwidth of 5 Gbps. This is more than twice the bandwidth needed to transmit multi-channel audio and video, future-proofing HDMI for some time to come.

CACHE MEMORY

Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there, it does not have to do the more time-consuming reading of data from larger memory.