Hard Disk

Hard Disk is a drive, which provides you to store your data for a long time. All your personal data like music, images, videos and files are saved by hard disk. Its basic measuring units are Gigabytes (GB) and Terabytes (TB). You can uninstall and save new data according to your demand. In case of more storage requirement, you can use external hard disk drive  as well. Seagate, Toshiba and Western Digital are largest manufacturers of internal hard disk while external hard disk are largely manufactured by ADATA, Freecom, LG, Samsung and Toshiba.

RAM:

RAM is the acronym of Random Access Memory, which is used for storage of computer data, not your personal data. This device is used to read and write data.  It temporary stores the computer memory and keep it until system is on and will erased it after your system go shutdown. RAM has two types SRAM (static RAM) and DRAM (dynamic RAM). It is available from 256MB to 8GB sizes. With increase in RAM size system will be able to perform faster than before.

                                                                                                                                                                                  Key Differences(RAM Faster then Hard Disk)

• All data you stored on hard disk are permanently saved during usage and after shutdown. While RAM keeps memory until system is running. All the memory will be erased automatically after your system switched off.
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• currently, RAM are available from 256MB to 8GB (recently announced by Seagate). While hard disk size starts where RAM size ends. 10GB to 8TB size hard disk are available in the market.
• RAM is just a chip containing some circuits. Hard disk is almost a machine having multiple parts like platters, plastic disc, magnate, writer & reader bar.
• If you are running short of hard disk space, you can use external hard disk for your data storage. There is no option for external remove                                                                                                      
• Whenever we perform some task, memory first comes from RAM instead of hard disk. Hard disk is a secondary mean for circulation of memory.
• RAM works faster than hard drive. Basic purpose of RAM is to fast the performance of system. If you have low RAM, your.
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                                                                                                                                                                                                                                                                                                                                                        A computer program maybe consisting of various functions and computations that it needs to execute...it also consists of instructions and data.. particularly information on which it needs to operate..

there ARE many ways by which a program executes..

in a very primary way.. any program is executed by the required source compiler..
or on a larger basis.. a program is executed via a central processing unit.. usually present within the system..

a computer requires certain programs and data for its proper functioning and this is done through a computer's central processing units..
there is always a sequence in the way the cpu executes any program..
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THE INSTRUCTIONS AND THE PROGRAM DATA.. WHILE EXECUTING A PROGRAM.. are always done via the memory unit within the cpu..
thr role of input devices;
input decvices play a vital role during program execution by allowing the user to input data to the system in order to work further on it..
e.g. keyboard mouse

the role of output devices
output devices  play their role by providing a platform to the system to display the results of the executed program..they display it on the screen in hard copy as well as in soft copy
e.g. monitor , printer 

Human beings are continuously engaged in some activity or other in order to satisfy their unlimited wants. Every day we come across the word 'business' or 'businessman' directly or indirectly. Business has become essential part of modern world.