What is a computer?
Computer is an electronic device that performs various types of calculations, which can be used in diverse ways. It was originally developed to perform mathematical operations, but it has now developed beyond that role. Today, computers are used in every conceivable part of life and their applications are innumerable.

 What is a computer made up of?
Any computer basically consists of a central processing unit and several peripheral units. The central processing unit consists of the processor, the main component that performs all the calculations. The peripheral devices are the ones that communicate with the CPU for input or output. The various components are the processor, motherboard, memory, hard disk, keyboard, mouse, CD/DVD reader/writer, monitor, joystick (controls for playing games) etc.

 What are the functions of these components?
The processor performs all the calculations and is the core of any computer. Any calculation performed must be kept in memory for retrieval. There are two types of memory, Random Access Memory (RAM) and static memory. RAM is used by the computer to store data temporarily and is volatile. Data is continuously written and erased from RAM and is lost when the computer is turned off. In order to retain the memory, data is stored in the form a digital file on a permanent basis (static memory). All data is saved permanently on memory storage device called hard disk in a computer. Data can also be written to other devices such as CD DVD or flash chips. Instructions are provided to the computer by input devices such as keyboard and mouse. The results of calculations are displayed visually as output on monitor screen. The image and video display is achieved using graphics card. Similarly there is a sound card, which is used to output audio. All the components of computer interact with each other on a major component called motherboard.

 I want to buy a computer, what features should I look for?
Purchase of a computer strictly depends on your use and budget. There are different configurations available to suit different needs. There are high-end computers with increased performance and are obviously costly. Such computers are usually required for gamers or "power users" who needs to run processor and memory intensive applications. For most users, a moderately configured computer should be sufficient. On should configure the components depending on the applications an user intends to run. A costly or advanced model may not perform better in a way that can be appreciated. Buyer should at least configure a processor, hard disk and monitor; the other components are bought that are either standard or complement the previous.

 Please give some information on processors.
Most importantly, start by selecting a processor. The top two players are AMD and Intel. They come in several models and designs. The most important component is the processor speed, which is measured in gigahertz (GH). Higher the number, the faster the computer is. Some processors have hyperthreading functionality built into it, which allows user to run multiple applications simultaneously without decreasing the performance of the other. Such processors are not in much use. Some processors have two processors running on them, some have four. Such processors are helpful when a user is running multiple applications at the same time. Such processor don't have high processor speed compared to the ones which have single core processor. Intel has a bigger market share than AMD. Other important aspect of the processor is the bus speed and the cache memory. Higher their values, the better.

 What about the motherboard?
The choice of motherboard depends on the choice of processor. There are different motherboards for AMD and Intel families of processors. Motherboard is usually chosen such that an advanced processor can be upgraded at a later stage; however it is sometimes difficult to guess which new processors it would support. Important considerations include number of USB ports, additional slots for graphics card, cooling system etc. Most motherboards come with integrated graphics and sound cards. While some come with air-cooled and some with liquid cooled solutions. More the USB ports, the better. Some advanced user look for over-clocking feature.

 What about the Hard disk?
Storage capacity is often the only feature that a buyer looks for. Hard disks are available with very high storage capacities. Currently, a storage space of 250 GB is considered optimum. Other features to look for include the spinning speed (7200 RPM), data access time, and cache memory. Higher values represent better (sometimes miniscule) performance. Presently most units come with SATA connectivity, which is faster that earlier PATA connectivity. Warranty and support is another important feature one must look for before choosing the model. Big players in this area include Western Digital, Samsung and Seagate.

 What about the RAM?
The present standard in RAM is DDR2. The minimum RAM required for XP users is 1 GB and can be 2 GB for Vista users. RAM must be chosen that is compatible with the motherboard. Since RAM is a very important component and there are many unbranded players in the market, many buyers get cheated. Zion and Hynix are top players in this segment. One must look for warranty and hologram before buying them.

 What about the display unit?
There are two types of units; CRT and LCD. LCD is becoming popular and cheaper. They consume less power, don’t emit any radiation and occupy less space on the table. One must look for the resolution and the size of the monitor.

What about the other components?
Scroll mouse has now given way for optical mouse. Scroll mouse are heavier and the ball gets stuck when dirt accumulates inside but work well on most surfaces. Optical mouse are lighter and work smoothly but can't work on all surfaces, a mouse pad is must. Most keyboards come in standard layout, some with extra features. Some companies provide both mouse and keyboard in a battery operated wireless models. SMPS and cabinets are other important components of the desktop computer. Cabinet with vents for sufficient cooling and SMPS with good voltage output are desirable.

 Which are other storage devices?
Floppy disks are no longer in use now. Data can be stored permanently or temporarily on devices for portability. Compact disc (CD) or Digital Versatile Discs (DVD) and flash memory drives (flash drive/thumb drive/pen drive) are used to save data. Data on most CDs and DVDs are neither editable nor erasable; hence they are only ROM (read only memory). Re-writable CDs and DVDs are also available where the entire disk can be erased and new data can be written. Data on these re-writable disks can’t be edited and individual files can’t be deleted. All the data are erased at once and made ready. Data written on these disks don’t remain for a lifetime. Mishandling these disks (scratches) can render them unreadable. While most CDs can hold 700 MB of data, common DVDs can hold 4.7 GB of data. Flash drives are used by plugging them into USB (universal serial bus) ports. Writing and accessing data from these devices are considerably faster than optical media (CD/DVD). These devices are available in wide range of storage capacities. While they are quicker, handy, easier to mount and remove, there are certain risks associated with it. Since they are smaller, it is easier to lose them and they readily get infected by viruses. External hard disks can also be used to store data.

 Which is better; assembled or branded?
Buying an assembled computer from a trustworthy vendor often works out cheaper than branded computers. In such cases, it is very important that the vendor assembles genuine components and undertakes to provide service and warranty. With assembled computers, user can configure the computer completely whereas branded computers can't be configured (except Dell). Branded computers can come with pre-installed softwares (for additional cost) and may provide support (depending on your location).

 Which is better; a desktop or a laptop?
This decision once again depends on your use and budget. If you must use computer on the move and want to take it with you for work, go for a laptop. The prices of laptop are falling and are becoming affordable. Laptops are available for a price ranging from Rs.20,000 to 1,50,000. Since laptops are not assembled by any vendor, buying the branded ones is the only choice. Most laptops cannot be upgraded; hence buying a relatively more advance laptop would be better. Configurations are important, just as in desktops. There are several players in this segment, to name some are; Lenovo, Sony, Compaq, Acer, Dell, Toshiba etc. While buying look for the processor, battery capacity, screen size, weight, RAM, hard disk capacity, number of USB ports, webcam, bluetooth, wi-fi connectivity, card readers, HDMI support, etc.

 What is hardware and software?
Hardware is the physical, tangible parts of a computer whereas the code of program that directs the computer to run is the software.

Next page >>