Secondary Storage

File Compression


File compression is the practice of packaging a file or files to use less disk space. It allows you reduce the overall number of bits and bytes in a file so it can be transmitted faster over slower Internet connections, or take up less space on a disk.



- An example of File compression software

Head Crash
A head crash is a hard-disk failure and it will cause significant damaga and date loss.. It can be initiated by a force that puts enough pressure on the platters from the heads to scratch through to the magnetic storage layer. Besides that, a tiny particle of dirt or other detritus, excessive shock or vibration, or accidentally dropping a running drive can also cause a head to bounce against its disk, destroying the thin magnetic coating on the area the heads come in contact with, and often damaging the heads in the process.

- An example of normal Hard Disc


-An example of Head Crashed Hard Disc

Internet Hard Drive


- Hugedrive.com is a website that provide Internet hard drive service.

 The Internet hard drive will allow you to save your computer files into a remote hard drive, and then later access those very same files from any other computer but with a condition ,which is  the computer has access to the Internet. 

Optical Disc Drive


- An example of Optical Disc Drive

In computing, an optical disc drive (ODD) is a disc drive that uses laser light or electromagnetic waves near the light spectrum as part of the process of retrieve or store data to or from optical discs. T his drives are commonly both readers and recorders so it can read retrieve and store data to or from Compact discs, DVDs and Blu0-ray discs.
Solid-State Storage


A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. SSDs are distinguished from traditional hard disc drives (HDDs) because it uses microchips which retain data in non-volatile memory chips and contain no moving parts. As a result, SSDs are typically less susceptible to physical shock, quieter, and have lower acces time and latency.

Input and Output

Engonomic Keyboard



An ergonomic keyboard is a computer keyboard designed with ergonomic considerations to minimize muscle strain and a host of related problems. It is more user friendly and comfortable to be used.

Ink-jet printer


An inkjet printer is a type of computer printer that creates a digital image by inserting variable-sized droplets of ink onto paper. Inkjet printers are the most commonly used type of printer because it is reliable, quiet, cheap and relatively inexpensive. It ranges from small inexpensive consumer models to very large professional machines .

Laser Printer



A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. Laser printers uses a technology similar with digital photocopies and multifuntion printers. What makes it unique is  that the image is produced by the direct scanning of a laser beam. It works faster and are used in applications that requiring high-quality output.


- picture shows how the laser printer work.

Magnetic-Ink Character Reader ( MICR)



Magnetic Ink Character Recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques. The technology allows computers to read information off of printed documents. For example, the unusual numbers on the bottom of checks and deposit cheque.

Optical-Character Recognition (OCR)

Optical character recognition (OCR) , is a method of making printed, typewritten or handwritten data understandable and readable with a computer. OCR is generally used to store the data in a digital format from where it can be edited on a machine and, most importantly, made searchable with keywords. Next, Optical Character Recognition involves deciphering the data by a machine, converting it into a machine readable format and storing it on the machine, which is usually a computer. A common OCR device is the handheld wand reader and usually used in department stores to read retail price tags.

- The picture shows how the OCR work.


Optical-Mark Recognition


Optical Mark Recognition (also called Optical Mark Reading and OMR) is the process of capturing human-marked data from document forms such as surveys and tests.

System Unit

Flash memory

Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for general storage and transfer of data between computers and other digital products.

 

-A USB flash drive. The chip on the left is the flash memory. The controller is on the right.

Graphic cards

A graphics card (also video 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.

Sound cards

A sound card (also known as an audio card) is a computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education, and entertainment (games).

- An example of cache memory card

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  local area network (LAN). 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. The network interface card acts as the liaison for the machine to both send and receive data on the LAN.

Plug and Play

In the world of computing, 'plug and play’ is a term used to describe the characteristic of a universal serial bus, or device specification, which facilitates the discovery of a hardware component in a system, without the need for physical device configuration, or user intervention in resolving resource conflicts.

Bus line

Device on a computer's motherboard that provides a data path between the Central Processing Unit (CPU) and attached devices. Examples of the devices are keyboard, mouse, disk drives and video cards. Like a vehicular bus that stops at an particular stations to pick up or drop off people, a computer bus receives a data signal from the CPU and drops it off at the appropriate device. Conversely, data signals from devices are sent back to the CPU. On a network, a bus provides the data path between the various computers and devices.

- An example of Bus line

High Definition Multimedia Interface (HDMI)

HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency (RF) coaxial cable.  HDMI connects digital audio/video sources (such as set-top boxes, upconvert DVD players, HD DVD players, Blu-ray Disc players, AVCHD camcorders, personal computers (PCs), video game consoles such as the PlayStation 3, Xbox 360, and AV receivers) to compatible digital audio devices, computer monitors, video projectors, and digital televisions.

-HDMI connector

- How HDMI work.

Cache memory

Cache (pronounced as cash) memory is extremely fast memory that is built into a computer’s central processing unit or located next to it on a separate chip. The Central Processing Unit (CPU) uses cache memory to store instructions that are repeatedly required to run programs, improving overall system speed. For examples in a computer with cache, the computer will copy the frequently used information into the cache. When needed, the Central Processing Unit will quickly acces the information from the cache.