what is the difference between CD and HARD DISK?

Answer 1

CD-ROM (an abbreviation "Compact Disc read-only memory" or "Compact Disc read-only media") is a Compact Disc that contains data accessible by a computer. While the Compact Disc format was originally designed for music storage and playback, the format was later adapted to hold any form of binary data. CD-ROMs are popularly used to distribute computer software, including games and multimedia applications, though any data can be stored (up to the capacity limit of a disc). Some CDs hold both computer data and audio with the latter capable of being played on a CD player, whilst data (such as software or digital video) is only usable on a computer. These are called Enhanced CDs.

Although many people use lowercase letters in this acronym, proper presentation is in all capital letters with a hyphen between CD and ROM. It is also debated whether the correct terminology is read-only memory or media. It is generally accepted that, in technical terms, media is the correct terminology. However, due to the widespread use of ROM to refer to other devices such as EEPROM and Flash-ROM (where memory is the correct terminology) most people define CD-ROM as also being memory as it sounds like the abbreviation is from the same origin.

HARD DISK
A hard disk (commonly known as a HDD (hard disk drive) or hard drive and formerly known as a fixed disk) is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to an entire unit containing multiple platters, a read/write head assembly, driver electronics, and motor while "hard disk" (sometimes "platter") refers to the storage medium itself. [1]

Hard disks were originally developed for use with computers. In the 21st century, applications for hard disks have expanded beyond computers to include digital video recorders, digital audio players, personal digital assistants, and digital cameras. In 2005 the first mobile phones to include hard disks were introduced by Samsung Group and Nokia. The need for large-scale, reliable storage, independent of a particular device, led to the introduction of configurations such as RAID, hardware such as network attached storage (NAS) devices, and systems such as storage area networks (SANs) for efficient access to large volumes of data.

Answer 2

A CD (Compact Disk) is an optical storage media, while a hard disk is a magnetic storage media. That's basically the difference.

On a CD the data is stored optically by burning with a laser beam the "grovees" of information by modulating the laser light beam with the digital data from a computer, reading or writting to/from the optical media.

On a hard disk however, the information is saved in magnetic grooves, just like a tape does on a tape deck, or any other audio recorder or even a digital tape recorder.

Both CD and hard disk work in random access mode, meaning the data is searched and found instantly, the heads go right to the data very quickly, the data is not written or read in a sequential manner like on an audio (or digital) tape for example, but in a well organized way where the system knows exactly where is the data stored and goes there in milliseconds.

Anything else? :)

I hope this helped.

Answer 3

'CD' stands for compact disk and it is a storage device of high capacity {usually 700MB}. The data in the CD can be read only from a CD drive. CD is a laser storage device and terms like 'etching' are used with regard to it. A few companies which produce CDs are: Moserbaer, Sony, Amkette, etc.
Whereas the hard disk is a magnetic storage device of very high storage capacity {usually 10GB or more}. It contains a series of platters onto which the data is stored. The hard disk is very sensitive to dust and humidity and thus is generally stored inside the CPU cabinet. Now a days portable hard disks are also available. Some of the companies producing hard disks are:
Seagate, Transcend, etc.

Answer 4

CD drive reads data from a read/write CD (such as that which stores music or software data). The drive uses a laser to read the disc that you insert and data (music, video, software...etc.) is read off the disk to display on your computer. CD drives can also record if you have a recordable drive and you can burn (write) data such as music files or word files to a disc for storage or everyday use.

Hard drives are a bit more difficult to explain, but better understood as the main drive that stores operating system software and other files. This drive is used to boot up your home pc. Other hard disk drives can be portable (removeable) for storage or backup, some hard disk drives are flash drives which are a faster type of data access architecture. If you want to know the internal workings of everything... surf the net.
I put a couple links to "howstuffworks" as a source for both that better describe this. Hope this helped.

Answer 5

Define Compact Disk

Answer 6

A hard disk holds far much more data than a cd and it holds the operating system and software of a computer on it. I cannot be removed unless it is a portable external drive. A CD can hold software where the data can be moved from one pc to another pc or to another appliance which can read the software format. Awful explaination sorry.

Answer 7

There is lot of difference b/w cd and hard disk both are r/w but cd means a compact one in the sense a minimum things we can see regarding size, cost, performance,where the hard disk plays major role in the computer, you can do work like devloping projects, executing programs,if you want to modify at any time in execution you can do, but while in cd you can you can not execute programs just temporary storage device.

Answer 8

yeh! as an engg. student i'm pleasure to answer ur question.

CD and HDD are of the same auxilllary memories but the major role which makes a differeence is the size and functionality.

CD is an optical device where as HDD is an electro magnetic device which contains metallic plates on which a magnetic coating is laid.

CD has the maximum capacity of 800 MB but the hard disk capacity is of nearly 1 tiga byte ( Tb ) .

its hard to load the OS from cd where as its easy to load from a hard drive because it is rewritable storage memory and is controlled by the processor itself.

bye yours praveen.

Answer 9

CD is the easily movable secondary data storage device where as the Hard Drive is the fixed secondary data storage device.

In terms of data access time the hard drive is fast and the CD is lslowly.

Currently all the professional software is available in the CD.


In terms of storage technique both used the same magnetic storage technique.

Answer 10

floppy has a minimum storage of 1.38/1.44 MB whereas hard disk has a range from 4 GB to 80 GB whereas CD has 700 MB floppy & hard disk are magnetic storage device Cd is a magneto-optical device