Information TechnologyInformation TechnologyIntroduction to ComputersIntroduction to Computers

Introduction to ComputersIntroduction to Computers

Definition Of Computers:Definition Of Computers:

““The Word Computer is derived from the word The Word Computer is derived from the word “compute” which means to calculate. The “compute” which means to calculate. The computer, therefore, can be defined as a computer, therefore, can be defined as a calculating device that can perform arithmetic calculating device that can perform arithmetic and logical operations.”and logical operations.”

““Computer is defined as a device that accepts Computer is defined as a device that accepts input, processes it and gives an output.input, processes it and gives an output.

Introduction to ComputersIntroduction to Computers

Input

Processing

Output

Types of ComputersTypes of Computers

Analog ComputersAnalog Computers

Digital ComputersDigital Computers

Hybrid ComputersHybrid Computers

Analog ComputersAnalog Computers

Analog computers are use to Analog computers are use to measure continuous values.measure continuous values. Examples of analog computers Examples of analog computers

are thermometers and analog are thermometers and analog clocks.clocks.

Digital ComputersDigital Computers

Digital means discrete. With Digital means discrete. With digital signals everything is digital signals everything is described in two states either described in two states either onon or or offoff, either 0 or 1., either 0 or 1. Examples of digital computers are Examples of digital computers are

digital watches and personal digital watches and personal computers.computers.

Classification of Digital Classification of Digital ComputersComputers

Super ComputersSuper Computers

Mainframe ComputersMainframe Computers

Mini ComputersMini Computers

Micro Computers/PCMicro Computers/PC

Super ComputersSuper Computers

Super Computers are the largest, the Super Computers are the largest, the fastest and the most expensive fastest and the most expensive computers in the world.computers in the world.

They handle huge amounts of data They handle huge amounts of data and can perform more than one and can perform more than one trillion calculations per second.trillion calculations per second.

They are used in weather They are used in weather forecasting, and modeling complex forecasting, and modeling complex processes like nuclear fission.processes like nuclear fission.

Mainframe ComputersMainframe Computers

They are based on the principle They are based on the principle of strong physical computing of strong physical computing power.power.

They are sensitive to variations They are sensitive to variations in temperature and environment.in temperature and environment.

They have a large storage They have a large storage capacity.capacity.

They can use a wide range of They can use a wide range of software.software.

Mini ComputersMini Computers

They were introduced in the They were introduced in the 60’s.60’s.

They have less capacity as They have less capacity as compared to mainframes.compared to mainframes.

They provide facility of direct They provide facility of direct operation.operation.

They were mainly used for data They were mainly used for data processing and in industry.processing and in industry.

Micro ComputersMicro Computers

They are commonly used They are commonly used nowadays.nowadays.

They are cheap and easy to They are cheap and easy to use.use.

They have limited input and They have limited input and output capacity.output capacity.

They are self-contained units They are self-contained units and are to be used by one and are to be used by one person.person.

Types of Micro ComputersTypes of Micro Computers

Desktop ComputersDesktop Computers

Laptop ComputersLaptop Computers

Palmtop ComputersPalmtop Computers

Desktop ComputersDesktop Computers

Single user machines.Single user machines. They can fit on a desk.They can fit on a desk. They can be interconnected to They can be interconnected to

form a network.form a network. Their speed depends upon the Their speed depends upon the

processor.processor. They are cheaper and sold in They are cheaper and sold in

millions.millions.

Laptop ComputersLaptop Computers

They are small, mobile personal They are small, mobile personal computers that can fit in your lap.computers that can fit in your lap.

They weigh from one to three Kg.They weigh from one to three Kg. They are also called Notebooks.They are also called Notebooks. They run on a battery or from an They run on a battery or from an

external AC/DC adapter that can external AC/DC adapter that can charge the laptop or supply the charge the laptop or supply the computer by itself.computer by itself.

Palmtop ComputersPalmtop Computers

These are computing devices These are computing devices small enough to fit in your palm.small enough to fit in your palm.

A Personal Digital Assistant is a A Personal Digital Assistant is a popular type of a palmtop.popular type of a palmtop.

Palmtops are also known as Palmtops are also known as handled PCs.handled PCs.

They are commonly used for They are commonly used for taking notes, e-mails and taking notes, e-mails and telephony.telephony.

Hybrid ComputersHybrid Computers

They are combinations of They are combinations of analog and digital computers.analog and digital computers.

They demonstrate qualities of They demonstrate qualities of both analog and digital both analog and digital computers.computers.

An example is cement plants.An example is cement plants.