Information technology (IT) is a technology which uses computers to gather, process, store, protect, and
transfer information. Today, it is common to use the term Information and communications
technology (ICT) because it is unimaginable to work on a computer which is not connected to the
network.
The computer consists of:
hardware – physical computer parts, palpable and visible
software – set of commands that are "understandable" to the computer; instructions to its
palpable parts, giving orders what to do
Basic principle of computers:
Data enters the computer through one or more input devices. The computer then processes the data and
transmits the resulting data to output devices. Output devices can be human interfaces such as a screen
or another electronic device such as a storage device or computer network.
The system unit consists of the following components:
Motherboard - MBO
o a computer "backbone" responsible for communication between components and
transmission of information
• Central Processing Unit - CPU
o functions: command execution, data transmission, computer function control
o basic characteristics:
• speed (in Mega Hertz (MHz), Giga Hertz (GHz))
• amount of memory (Cache in Bytes)
Random Access Memory - RAM
o a memory container for programs that are currently running and data that is being
processed
o basic characteristics:
• speed (in MHz, GHz)
• capacity (in Bytes)
• data rate class (DDR SDRAM, SDR SDRAM)
permanent memory:
o Hard Disk Drive - HDD - device (memory) used for permanent data storage
• data is stored on magnetic platters; electromagnetic heads are used for reading and
recording data with the exception of the newest disk types called Solid State
Drive (SSD)
• basic characteristics:
disk platters rotation speed (in RPM)
capacity (in GB)
connection interface (IDE, SATA)
o Floppy Disk Drive - FDD
o optical disks - CD, DVD
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, graphics processing units (GPU)
o function: processing and displaying image on the monitor
o it consists of a graphics processor and its own working RAM memory
o basic characteristics:
• type of graphics processing units (ATI Radeon, NVidia GeForce, or other)
• RAM size
• connection interface/slot type
ports:
o Parallel Port
o Serial Port
o Universal Serial Bus (USB)
Input and output devices
Input devices: Output devices:
o keyboard o monitor
o scanner o projector
o touchpad o printer
o mouse o plotter
o trackball o speakers
o joystick o earphones
o microphone
o stylus
o camera (web, digital)
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