The document provides an overview of computer systems, defining a computer as a programmable electronic device that processes data into meaningful information. It outlines the components of a computer system, including hardware, software, and users (liveware), and categorizes hardware into various types, such as the processor, memory, storage, and communication devices. Key components like CPU, RAM, and ROM are described with their functions and characteristics.

1. BIT
Computer Systems
Overview of Computer Systems
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2. What is a Computer…?
• Man-made, programmable electronic machine that can store,
retrieve, and process data according to a given set of
instructions
• Simply we can say ‘It is electronic/intelligent device which can
convert raw DATA in to meaningful INFORMATION ’
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3. DATA
• Data can be defined as ‘Raw facts’, ’Meaning less
things’ or ‘Un-processed things’
• Normally data can be input to a system.
• E.g.- In an organization: employee’s name, number of
hours of work, employee address, and employment
commenced date, etc
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4. INFORMATION
• Processed data and which has a meaning
unlike data.
• Normally Information are output from a
system.
• E.g.-In an organization: monthly salary of an
employee, total sales in a particular month,
etc
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5. Total Computer System
• A system is a collection of elements that work together to
achieve a common objective.
Total
Computer
System
Hardware Software Liveware
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6. Total Computer
System
Hardware Software Liveware
System Software Application Software
Packages
Languages
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7. Computer Hardware
• The physical components (tangible parts) of a
computer known as Hardware.
• E.g.- System unit, Mouse, Keyboard, Monitor
etc 7
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8. Software
• Collection of programs or applications, which
contain the instructions that makes the
computer work.
• E.g.-
Windows XP, Ms-Word, Java, AVG, Virus,
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9. Liveware
• The computer users are known as Liveware.
• It can be anyone who use the computer.
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10. Hardware categorization
• Mainly computer Hardware can be
categorized as follows,
– Processor/CPU
– Memory & integrating devices
– Input devices
– Output devices
– Storage devices
– Communication devices
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11. Processor/CPU
• Can be defined as the ‘Brain’ of the computer.
• All the commands are execute from here.
• Mainly consists with two parts,
»ALU
»CU
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12. ALU-Arithmetic & Logic Unit
• Responsible for performing Arithmetic
functions such as,
– Addition (+)
– Subtraction (-)
– Division(/)
– Multiplication(*)
• And Logical functions like,
– Is Greater than (>)
– Is Less than(<)
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13. CU-Control Unit
• Responsible for controlling all the Hardware of
the computer and all the Software of the
computer.
• All tasks of the computer has been runs under
the direct co-ordinations of CU.
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14. Memory
• There are two types of memories within
computer,
– RAM (Random Access Memory)
– ROM (Read Only Memory)
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15. RAM
• Random Access Memory.
• The currently processing data are held within
the RAM.
• Measures as a capacity. (MB,GB)
• Temporary, Volatile.
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16. ROM
• Read Only Memory.
• If Compare with the RAM has low capacity.
(Measures with KBs)
• Contain a special software called ‘Firmware’, which
use to turn on the computer (booting) properly by
recognizing the Hardware devices at the system
start-up.
• Firmware also known as ‘BIOS’, Start-up program,
‘CMOS’ setup.
• Non-volatile, Permanent memory type
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17. Storage Devices
• The memory locations where use to store
Data/Information permanently.
• E.g.
– HDD (Hard Disk Drive)
– CD-ROM
– DVD-ROM
– Tape Drive
• Much large in capacities. (Measures by using
MBs or GBs)
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18. Communication Devices
• Hardware devices use for the communication
purposes.
• E.g.
– MODEM
– Router
– Switch/Hub
– Repeater
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