Welcome to the computer world. Practice materials for 1st year students. Еранина Т.И - 20 стр.

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1) input hardware
2) processing hardware
3) storage hardware
4) output hardware

                    Input hardware

            Input hardware collects data and convert them into a form
suitable for computer processing. The most common input device is a
keyboard. It looks very much like a typewriter. The mouse is a hand-
held device connected to the computer by a small cable. As the mouse
is rolled across the desktop, the cursor moved across the screen. When
the cursor reaches the desired location, the user usually pushes a button
on the mouse once or twice to give a command to the computer.
            Another type of input hardware is optic-electronic scanner.
Microphone and video camera can be also used to input data into the
computer.

                  Processing hardware

            Processing hardware directs the execution of software
instructions in the computer. The most common components of
processing hardware are the central processing unit and main
memory.
            The central processing unit (CPU) is the brain of the
computer. It reads and interprets software instructions and coordinates
the processing.
            Memory is the component of the computer in which
information is stored. These are two types of computer memory: RAM
and ROM.
            RAM(random access memory) is the memory, used for
creating, loading and running programs.
            ROM(read only memory) is computer memory used to hold
programmed instructions to the system.
            The more memory you have in your computer, the more
operations you can perform.

                     Storage hardware

           The purpose of storage hardware is to store computer
instructions and data and retrieve when needed for processing. Storage
hardware stores data as electromagnetic signals. The most common
ways of storing data are Hard disk, floppy disk and CD-Rom.