COMPUTER HARDWARE
It refers to objects that you can actually touch, like disks, disk drives,display screens, keyboards, printers, boards, and chips. In contrast,software is untouchable. Software exists as ideas, concepts, and symbols, but it has no substance.Books provide a useful analogy. The pages and the ink are the hardware, while the words, sentences, paragraphs, and the overall meaning are the software. A computer without software is like a book full of blank pages -- you need software to make the computer useful just as you need words to make a book meaningful.
HARDWARE COMPONENTS
1.MOTHERBOARD
Now, the first thing is the motherboard. It's the basis of your computer. It's the first component installed in the system unit, and it holds all of the circuitry that ties the functions of the computer components together.
You can think of it like your car (which has many computer systems of its own). If you have a frame and tires, you've got a car (or you've got a system unit), but it won't take you very far! Now, add your engine - the motherboard - where all the systems tie in one way or another, and you've got the start of a working vehicle.
2.CENTRAL PROCESSING UNIT
The central processing unit, or the brains of the computer, sits on the motherboard and does actually have its own cooling fan. The processors now are so fast they need to be cooled down. All the instructions you give the computer - like a click of a mouse - go through the CPU, which processes in billions of cycles per second.
3.RANDOM ACCESS MEMORY
Random-access memory (RAM) is a type of computer data storage. A RAM device makes it possible to access data in random order, which makes it very fast to find a specific piece of information. Certain other types of storage are not random-access. For example, a hard disk drive and a CD will read and write data in a predetermined order. The mechanical design of these devices prescribes that data access is consecutive. This means that the time it takes to find a specific piece of information can vary greatly depending on where it is located on the disc.RAM devices are used in computer systems as the main memory. RAM is considered volatile memory, which means that the stored information is lost when there is no power. So, RAM is used by the central processing unit (CPU) when a computer is running to store information that needs to be used very quickly, but it does not store any information permanently.Present-day RAM devices use integrated circuits to store information. This is a relatively expensive form of storage and the cost per unit of storage is much higher than for devices like a hard drive. However, the time to access data is so much faster for RAM that speed outweighs cost. A computer therefore uses a certain amount of RAM for fast-access, temporary storage of information and a much larger amount of non-random, permanent mass storage, like a hard disk drive. For example, a typical computer system may have two to eight GB (gigabytes) of RAM.
3.CACHE MEMORY
Cache memory, also called CPU memory, is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU.The basic purpose of cache memory is to store program instructions that are frequently re-referenced by software during operation. Fast access to these instructions increases the overall speed of the software program.As the microprocessor processes data, it looks first in the cache memory; if it finds the instructions there (from a previous reading of data), it does not have to do a more time-consuming reading of data from larger memory or other data storage devices.Most programs use very few resources once they have been opened and operated for a time, mainly because frequently re-referenced instructions tend to be cached. This explains why measurements of system performance in computers with slowerprocessors but larger caches tend to be faster than measurements of system performance in computers with faster processors but more limited cache space.Multi-tier or multilevel caching has become popular in server and desktop architectures, with different levels providing greater efficiency through managed tiering. Simply put, the less frequently access is made to certain data or instructions, the lower down the cache level the data or instructions are written.
4.READ ONLY MEMORY(ROM)
Computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read.Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile.
TYPES OF ROM
Electrically Programmable Read-Only Memory (EPROM)
Electrically Erasable Programmable Read-Only Memory (EEPROM; also called Flash ROM)
Electrically Alterable Read-Only Memory (EAROM)
5.MOUSE
A device that controls the movement of the cursor or pointer in a display screen. A mouse is a small object you can roll along a hard, flat surface. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse's tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction. Mice contain at least one button and sometimes as many as three, which have different functions depending on what programe is running. Some newer mice also include a scroll wheelfor scrolling through long documents.
6.KEYBOARD
A keyboard is the set of typewriter-like keys that enables you to enter data into a computer and other devices. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys.
7.MODEM (mō´dem) (n.) Short for modulator-demodulator
A modem is a device or programe that enables a computer to transmit data over. for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.
