Computer Definition: A computer is a programmable machine (usually electronic), capable of receiving digitalized non-manipulated data (text, number, image, video, audio), process it, and produce a result in the form of information (meaningful data) that could be understood.
Data: facts and figures (numbers, text, images, videos, and audios etc), either could be in a raw format is called data.
Information: a processed and meaningful data is called information.
The modern computer is based on electronic and digital. It consists of hardware and software, i.e. wires, transistors and ICs (integrated circuits) and software, i.e., system software and application software.
The name of a computer has derived from a Latin word “computare” means “to calculate”. Hence it can perform the arithmetical calculation, e.g. Adding, Subtracting, Multiplying and dividing to find an immediate answer to the problems.
A computer is now used in each place of work. It uses to type documents, send email, doing accounting job, keeping of record. It also uses by various departments, i.e. engineering, education, health, banks, industries, stores, markets, judicial, police, defense, and telecommunication etc.
Parts of a Computer:
A personal computer is not a single component, but it consists of different parts. Following are the basic parts of a computer. It generally refers to the hardware.
- CPU (Central Processing Unit): this is the main component of a computer. It is known as the brain of the computer. All the programs (list of instructions) are executed in this part.
- RAM (Random Access Memory): a primary memory which allows the computer to store (temporarily) the entire executing program.
- Mass Storage Device (Hard Drive): a secondary memory which allows the computer to store large amount of data permanently and can retrieve it again and again.
- Input Devices: these are the devices which allow the user to feed data/instructions to the machine, i.e. keyboard, mouse, scanner and CD-ROM etc.
- Output Devices: these are the devices that allow the users to see the final result (information).
- Bus: it is a communication system that transmits data from one component to another inside a machine. This refers to hardware (wires, optical fibers etc.) as well as software (communication protocols).
Stages of Development:
A computer has passed through many stages.
- Abacus: it was the first calculating device developed in China before (3000 BC) for calculation.
- Napier’s Bone: in the early of 1617 John Napier a Scottish mathematician invented this device which can perform an accurate operation and multiplication of large numbers.
- Oughtred’s Slide Rule: it was invented by an English Mathematician Wilheim Oughtred which can do both multiplication and division operation.
- Pascaline: 19 years old French boy “Blais Pascal” developed the 1st Mechanical Calculator called P
- Leibnitz Machine: In 1694 a German Mathematician Wilhelm Leibnitz completed a machine which could perform multiplication, division, and square roots.
- Jacquard’s Loom: in 1801 Joseph Jacquard a French Textile manufacturer invented the punch card to create patterns in fabric woven on a loom.
- Difference Engine and Analytical Engine: In 1823 a British Professor at Cambridge University “Charles Babbage” conceived the programmable machine. He is considered father of the modern digital computer.
- Data Processing Machine: In 1890 Dr.Herman Hollerith developed the 1st electromechanical data processing machine, in which programs stored through a punch card.
- Mark-I: In 1937 Haward an Aiken at Haward University began a project with IBM and completed in 1944.he developed a 1st digital computer of the world called “MARK-I”.
A computer is generally classified into the following types.
On the Basis of Power and Size:
- Microprocessor: a type of single-user computer; based on microprocessors. It is also called a personal computer. Many input and output devices can attach to this.
- Workstation: a terminal or a single-user computer which connected to a network (with supper or mainframe) and more powerful than a microprocessor.
- Minicomputer: a type of multi-user (multiprocessing) computer capable to handle (10 to 100) users simultaneously.
- Mainframe: it is a large and expensive multi-user (multiprocessing) computer capable of supporting more than 100 users simultaneously.
- Supercomputer: it is a faster, more powerful and expensive multi-user calculating device, and calculating million of instructions per second up to 14 accurate decimal places. It is also called “Number Cruncher”.
On the Basis of Functionality:
- Analog: analog means variable and physical quantity. A computer which works with continued changes in numbers.
- Digital: this type of computer measures data in term of digital quantity.
- Hybrid (Analog + Digital): a computer which measures both analog and digital types of data.