INTERNAL COMPUTER HARDWARE
POWER SUPPLY
 Metal box inside the system unit that distributes electricity from an outlet to the
various system components; includes a fan that cools internal components
CENTRAL PROCESSING UNIT (CPU)
 The brain centre of the computer; executes commands/performs calculations;
CPU capability determines speed/power; speed is measured in gigahertz (GHZ)
MOTHERBOARD
 A board that holds the internal circuitry; the CPU attaches to the motherboard
BUS
 Main communication path on the motherboard that connects the system’s
components with the CPU; contains expansion slots to connect additional
external and internal components
RANDOM ACCESS MEMORY (RAM)
 Temporary memory that stores current programs and data as long as it has
electricity; capacity is measured in megabytes (MB) and
gigabytes (GB)
READ ONLY MEMORY (ROM)
 Permanent memory that contains preprogrammed instructions available to the
CPU as soon as the computer is turned on; these instructions load the PC’s
operating system
AUDIO/SOUND CARD
 a printed circuit card that processes sound files and sends them to the
computer's speakers
VIDEO/GRAPHICS CARD
 a printed circuit board that controls the output to a display screen.
CABLES
 devices that connect components to the motherboard
MODEM
 An input/output device; transfers information between PC and global network of
computers (internet)
WEBCAM (May also be EXTERNAL)
 a video camera that inputs to a computer connected to the Internet, so that its
images can be viewed by Internet users
SPEAKERS (May also be EXTERNAL)
 device attached to internal audio card in order for sounds to be transferred
externally
The following devices are also considered STORAGE DEVICES:
HARD DISK DRIVE
 Operates the hard disk which is comprised of magnetic storage material; holds
the computer’s system files, programs and data files; measured in gigabytes
(GB)
FLOPPY DISK DRIVE
 Retrieves and stores files on a removable 3.5” floppy disk
UNIVERSAL SERIAL BUS DRIVE (USB)
 Retrieves and stores files on a removable device; also known as a flash, thumb,
or jump drive; approximate size = 2. 25” x 1”
COMPACT DISC – READ ONLY MEMORY DRIVE (CD-ROM)
 Input device containing ROM
COMPACT DISC – RE-WRITABLE DRIVE (CD-RW)
 Input/output device commonly known as a CD Burner
DIGITAL VIDEO DISC DRIVE (DVD)
 Input device for viewing video
DIGITIAL VIDEO – RE-WRITABLE DRIVE (DVD RW)
 Input/output device for viewing and recording video