Technology Lesson Resources


A Computer is an electronic device that is designed to work with Information by completing 4 basic steps:
  • Accepting Data (Input)
  • Processing the data according to specific instructions (Process)
  • Outputting Information or post-process data for further processing e.g creating a alphabetic list of names from names inputted  (Output)
  • Storing the post-process data or information for further processing or usage (Storage)
The term computer is derived from the Latin term ‘computare’, this means to calculate or programmable machine. Computer can not do anything without a Program. It represents the decimal numbers through a string of binary digits. The Word 'Computer' usually refers to the Center Processor Unit plus Internal memory. Charles Babbage is called the "Grand Father" of the computer. The First mechanical computer designed by Charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards. Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves (storage) output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations.

Digital Computer Definition

The basic components of a modern digital computer are:
  • Input Device,
  • Output Device,
  • Central Processor Unit (CPU),
  • Mass storage device and
  • Memory.
A Typical modern computer uses LSI Chips.

Four Functions about computer are:

1. accepts data - Input
2. processes data - Processing
3. produces output - Output
4. stores results - Storage

Input (Data):

Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc. 


  Process is the operation of converting or arranging data as per given instruction to a specific format. It is a totally internal process of the computer system.


Output is the processed data given by computer after data processing. Output is also called as Result.


We can save these results in the storage devices for the future use.

Computer Classification: By Size and Power

Computers differ based on their data processing abilities. They are classified according to purpose, data handling and functionality.
According to functionality, computers are classified as: 
•Analog Computer:  A computer that represents numbers by some continuously variable physical quantity, whose variations mimic the properties of some system being modeled.
• Personal computer: A personal computer is a computer small and low cost. The term"personal computer" is used to describe desktop computers (desktops).
• Workstation: A terminal or desktop computer in a network. In this context, workstation is just a generic term for a user's machine (client machine) in contrast to a "server" or "mainframe."
• Minicomputer: A minicomputer isn't very mini. At least, not in the way most of us think of mini. You know how big your personal computer is and its related family.
• Mainframe: It refers to the kind of large computer that runs an entire corporation.
• Supercomputer: It is the biggest, fastest, and most expensive computers on earth.
• Microcomputer: Your personal computer is a microcomputer.

Source: EComputer Notes>

What is CPU:

It's meaning is Central Processing Unit. Sometimes referred to simply as the central processor or Nerve Centre or heart, but more commonly called processor, the CPU is where most calculations take place. The CPU is the brains of the computer.

CPU Definition

Central processing unit (CPU) is the central component of the Computer System. Sometimes it is called as microprocessor or processor. It is the brain that runs the show inside the Computer.
All functions and processes that is done on a computer is performed directly or indirectly by the processor. Obviously, computer processor is one of the most important element of the Computer system.
CPU is consist of transistors,that receives inputs and produces output.Transistors perform logical operations which is called processing. It is also, scientifically, not only one of the most amazing parts of the PC, but one of the most amazing devices in the world of technology.
In terms of computing power, the computer processor is the most important element of a computer system. It add and compare its data in cpu chip. A CPU of all computers, whether micro, mini or mainframe must have three parts.

Parts of CPU

Arithmetic Logic Unit (ALU): It is the part of computer processor (CPU) can be used to perform arithmetic and logic operations. An arithmetic-logic unit (ALU) is further divided into two parts, (AU) arithmetic unit and a (LU) logic unit.

Control Unit (CU): Decodes the program instruction. CPU chip used in a computer is partially made out of Silica. on other words silicon chip used for data processing are called Micro Processor.

Registers: It is temporary storage areas of the computer processor. It is managed by control unit(CU).Registers holding data,instruction and address that are needed by program while running.

The processor plays a significant role in the following important aspects of your computer system:

Performance: The processor is probably the most important single determinant of system performance in the Pc. While other components also playa key role in determining performance, the processor's capabilities dictate the maximum performance of a system. The other devices only allow the processor to reach its full potential.

Software Support: Newer, faster processors enable the use of the latest software. In addition, new processors such as the Pentium with MMX Technology, enable the use of specialized software not usable on earlier machines.

Reliability and Stability: The quality of the processor is one factor that determines how reliably your system will run. While most processors are very dependable, some are not. This also depends to some extent on the age of the processor and how much energy it consumes.

Energy Consumption and Cooling: Originally processors consumed relatively little power compared to other system devices. Newer processors can consume a great deal of power. Power consumption has an impact on everything from cooling method selection to overall system reliability.

Motherboard Support: The processor that decides to use in your system will be a major determining factor in what sort of chipset we must use, and hence what motherboard you buy. The motherboard in turn dictates many facets of the system's capabilities and performance.

Source: EComputer Notes>
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How Computers Work

Binary & Data

CPU, Memory, Input & Output

CPU, Memory, Input & Output

Hardware and Software

Bits, Bites & the Internet

Operating Systems

The Components Inside Your Computer


Related Information

Computer Technology