Input Devices:
Devices
used to provide data and instructions to the computer are called Input devices.
Some
important input devices are
Key board,
Mouse, Scanner,
MICR,
Web camera,
Microphone.
Output devices:
Any
device that is capable of representing information on a computer is called an
Output device. Output devices receive information from the CPU and present it
to the user in the desired form.
Some important Output devices are:
Monitor,
Printer
MEMORY
OF THE COMPUTER:
Memory
or storage capacity is one of the important components of a computer. Any
storage unit of a computer system is classified on the basis of the following
criteria:
1.
Access time: This is the time required to locate and retrieve stored data from
the storage unit in response to program instructions.
2.
Storage capacity: It is the amount of data that can be stored in the storage
unit.
3. Cost per bit of storage.
Types
of Memory: A computer memory is of two types
- Primary Memory ( Internal storage)
- Secondary Memory ( External storage)
Primary
Memory: Primary memory is also called internal memory and is an
important part of a computer. It is the main area in a computer where the data
is stored. The stored data can be recalled instantly and correctly whenever
desired. This memory can be quickly accessed by the CPU for reading or storing
information. Primary memory is further classified into two types:
- Random Access Memory (RAM)
- Read- Only Memory (ROM
)
Secondary
memory: The primary memory which is faster (and hence expensive) is
generally not sufficient for large storage of data. As a result, additional
memory, called the auxiliary or secondary memory‖ is used. It is also referred
as backup storage as it is used to store large volume of data on a permanent
basis which can be transferred to the primary memory whenever required for
processing.
.
Some
of the devices of secondary storages are
·
Floppy Disk,
·
Hard Disk,
·
CD-ROM,
·
DVD and
·
Flash drive.
.