com 1013 data storage

17

Upload: puteri-sabah

Post on 09-Jul-2015

39 views

Category:

Devices & Hardware


0 download

DESCRIPTION

ENJOY

TRANSCRIPT

Page 1: COM 1013 Data storage
Page 2: COM 1013 Data storage

Computer data storage, often called storage or memory, is atechnology consisting of computer components andrecording media used to retain digital data.

The central processing unit (CPU) of a computer is whatmanipulates data by performing computations.

CPU consists of two main parts: control unit & arithmeticlogic unit (ALU).

volatile technologies (which lose data when powered off) arereferred to as "memory", while slower permanent technologiesare referred to as "storage",

Page 4: COM 1013 Data storage
Page 5: COM 1013 Data storage

Random Access Memory (RAM)Random access memory is used as a scratch pad by thecomputer processor to store information temporarily. RAMis a volatile memory that loses information as soon as youturn off the computer. However, the access rate of this typeof memory is greater than the read only type of memory.Access rate of the memory is the time required by to get anaccess to the memory.

Read Only MemoryRead only memory (ROM) is a type of storage that is used tostore information permanently. Either the data is stored inthis type of memory at the time of manufacturing or isstored by the computer user. But the data cannot be changedonce written (non-volatile). The access rate of this type ofprimary storage is less than RAM.

Page 6: COM 1013 Data storage
Page 7: COM 1013 Data storage

The secondary storage is non-volatile and can retain information evenafter the computer is switched off.

Hard Drives

Hard drives are crucial secondary storage devices that are used in acomputer. There are different hard drive types. Hard disk drives are non-volatile and data is stored in a digital form on the platters that havemagnetic surface. The hard disk drives were used as a removable massstorage device. However, nowadays, the hard disks come as a completesealed unit inside the CPU. Portable hard disk drives are also availablenow.

Blu-ray Discs

These discs are often used by gamers and also for high-definition video storage. According to the physical dimensions, the BD are similar to that of the CDs and DVDs; however, the only difference is that the capacity of a BD is very large as compared to CDs and DVDs. BD are optical storage devices.

Page 8: COM 1013 Data storage

The secondary storage also includes offline storage devices, which are those secondary storage devices in which information is stored and then they are disconnected from the computer.

They include CDs and DVDs.

The main aim of storing data offline is to increase the security of information, besides using up less space in the computer itself, and also act as a backup of data.

Page 9: COM 1013 Data storage

Compact DiscsCDs were used to record audio files, but later on they started being used to store every type of information like video, audio and data. CDS are used to store information over a long period of time. CDs store information optically and are non- volatile.

Digital Versatile Disc (DVD)DVDs store data in the same manner as that of the CDs. However, DVDs have a greater storage capacity than the CDs. A DVD have a capacity which is six times greater than the storage capacity of a CD.

Flash MemoryFlash memory is a further advancement in the read only memory with the difference that the information in the flash memory can be electrically erased within seconds. Also, the data that is stored in the flash memory can be changed according to the use.

Page 10: COM 1013 Data storage
Page 11: COM 1013 Data storage

Tertiary storage is the third type of data storage. Thisincludes the devices that are connected to thecomputer in the form of removable mass storagedevices. It is often used to store those files that arerarely accessed by the computer user.

USB Flash DrivesUSB flash drives are connected to the computer viathe USB port of the computer cabinet and use theUniversal Serial Bus (USB) interface to storeinformation. They are rewritable and have in-builtflash memory inside them.

Page 12: COM 1013 Data storage

Off-line storage is a medium or a device that is not under the CPU. The medium is recorded, usually in a secondary or tertiary storage device, and then physically removed or disconnected. It must be inserted or connected by a human operator before a computer can access it again. Unlike tertiary storage, it cannot be accessed without human interaction.

Off-line storage is used to transfer information, since the detached medium can be easily physically transported.

For example a fire, destroys the original data, a medium in a remote location will probably be unaffected, enabling disaster recovery.

Off-line storage increases general information security, since it is physically inaccessible from a computer, and data confidentiality or integrity cannot be affected by computer-based attack techniques.

Optical discs and flash memory devices are most popular, and to much lesser extent removable hard disk drives. In enterprise uses, magnetic tape is predominant(“utama’’). Older examples are floppy disks, Zip disks, or punched cards.

Page 13: COM 1013 Data storage
Page 14: COM 1013 Data storage
Page 15: COM 1013 Data storage

Cloud computing is the next stage in the Internet'sevolution, providing the means through whicheverything — from computing power to computinginfrastructure, applications, business processes topersonal collaboration — can be delivered to you as aservice wherever and whenever you need.

The “cloud” in cloud computing can be defined as theset of hardware, networks, storage, services, andinterfaces that combine to deliver aspects ofcomputing as a service.

Page 16: COM 1013 Data storage

For instance, there are currently online companies that offer back-up services for you. This means that you can simply downloadtheir program, and they'll automatically backup all your filesperiodically. So if your computer dies or gets infected with a virusor something, you can get back your old files online from the back-up company. (Of course, you have to pay a fee for this service;IT'S NOT FREE.)

Page 17: COM 1013 Data storage