Central Processing Unit (CPU)
also called “The Chip”, “Microprocessor” or simply “The Processor”
Main Memory (RAM)
CPU or microprocessor is often described as the brain of a
CPU is an integrated circuit or “chip” which processes
instructions and data.
CPU speed or CPU performance is measured by the
completed Instruction Cycles Per Second (IPS).
Currently, CPU speeds range from
600 megahertz (MHz or million cycles
per second) to 4 gigahertz (GHz or
billion cycles per second).
Processing performance of computers is increased by using
multi-core processors, which essentially is plugging two or
more individual processors (called cores in this sense) into
one integrated circuit.
(Eg: Intel Core i5, AMD Phenom II X4, …)
RAM or Random Access Memory
It is a volatile type of memory
Holds instructions for processing
data, processed data, and raw data.
Ram is measured by:
Capacity (in Megabytes or Gigabytes)
Frequency (in MHz)
Amount of RAM installed will determine.
Which software applications will run
How many software applications can be open
simultaneously? (multitasking ability)
Types of RAM:
SRAM (Static RAM)
DRAM (Dynamic RAM)
Magnetic storage devices store data by
magnetizing particles on a disk or tape.
Optical storage devices store data as light
and dark spots on the disk surface.
Hard Disk Drives
Capacity is measured in gigabytes (GB or
billions of bytes).
Typically permanently installed.
Used to store operating system, application
software, utilities and data.
Magnetic storage device.
Other Storage Devices :
CD, DVD, BD…
External Hard Drives
USB Flash Drive (Pen drive orThumb drive)
Input devices gather and translate data
into a form the computer understands.
Primary input device:
Keyboard - Most common input device; used to
type in commands and data.
Mouse or Trackball enhances user’s ability to
input commands, manipulate text, images.
Joystick useful for Gaming
Monitors are the most commonly used
Most monitors use a bitmap (Raster) display.
Allows user to resize the display.
Divides the screen into a matrix of tiny square “dots”
The more “dots” a screen can display, the higher the
resolution of the monitor.
For example: CRT(Cathode RayTube), LCD (Liquid Crystal
Other output devices: