Q. What is Computer?
Answer: A computer is an electronic machine which stores, read and processes data to produce meaningful information as output.
Components of Computer
Q. What is Input Unit?
Answer: This Devices used to given instructions, like, keyboard, mouse, joystick, optical character reader, CDs Bar code reader, Touch screen, Light pen, Scanner, Magnetic INK Character Recognition (MICR), etc.
Q. What is Central Processing Unit?
Answer: Central Processing Unit (CPU) is the device for the manipulation of information inside the computer. CPU is also known as the brain of the computer, but commonly called a processor.
It has the following components.
Arithmetic logic Unit (ALU) – It performs all logical and arithmetical operations.
Control Unit (CU) – It Instructs, maintains and controls the flow of information.
Output Unit – It is the device to display the result of processing, e.g. Visual Display Unit, Printer, Monitor, Speaker, Pen Drive and more.
Q. What is Memory?
Answer: A Memory holds all the raw and processed data, set of instructions and information inside the CPU.
Q. What is Primary Memory?
Answer: A primary Memory stores the data which is currently in use by the computer.
Q. What is RAM?
Answer: RAM stand for Random Access Memory is a volatile memory. It is a temporary storage. It divides into two parts.
- DRAM – Dynamic Random Access Memory
- SRAM – Static Random Access Memory
Q. What is ROM?
Answer – ROM stand for Read only memory it is a non-volatile memory where all logical data is stored that cannot be changed. It divides into two parts.
- PROM – Programmable Read Only Memory
- RPROM – Erasable Programmable Read Only Memory
- EEPROM – Electrically Erasable Programmable Read Only Memory
It stores data, program, instruction and information permanently.
Any peripheral device which can be seen and touched is hardware. Computer hardware includes input devices, output, devices and processing devices.
It is a set of instructions that directs the computer to process information. It can be classified as
System Software – It is background software that helps the computer to manage its own internal resources. i.g. Operating system, Device driver and Language Translator etc.
Application Software – It is a set of programs designed for specific uses or applications, e.g. word processor spreadsheet, accounting programs, etc.
Computer networking related to the communication between a group of two or more computers linked together. Most common example of networking is Internet, connecting millions of people all over the world together. According to scale or size, computer network can be categorized in three ways.
(i) Local Area Network (LAN) – Graphical area spread over 1 km to 10 km or within a same building.
(ii) Metropolitan Area Network (MAN) – Graphical area spread over a city or town.
(iii) Wide Area Network (WAN) – Graphical area spread over countries.
(i) Worm – It is a self-contained program and does not need to be a part of another program to propagate itself.
(ii) Spam – Spam is an unsolicited message sent over the internet in the form of e-mails, to a large number of users for the purpose of spreading malware, advertising phishing, etc.
(iii) Spyware – IT is a type of malicious software installed on computer and collects information about users without their knowledge and may send such information to another entity.
(iv) Malware – software which is specifically designed to disrupt or damage a computer system. It is a superset of computer viruses, worms, spyware, Trojan horses and other malicious or unwanted software.
(v) Virus – A virus is defined as program or a piece of code that gets loaded onto the computer without users knowledge and replicates itself, e.g. Creeper, Stuxnet, Melissa, Conficker, Code red, SQL, Stammer, Nimda (derived from the word ‘Admin’), etc.
Antivirus – Antivirus is a software consisting of computer programs that attempt to identify, detect and prevent the malware from the computer.
Some Commonly Used Terms
Cache Memory – It is a temporary storage, where frequently accessed data can be stored for rapid access.
Registers – These are defined as the special memory units used by the CPU to speed up the rate of accessing information.
Operating System – It is system software, consisting of an integrated set of programs that control computer resources and provides common services for efficient execution of various application software.
Complier – It is a computer program that transforms human readable source code into the machine readable code at one go.
Interpreter – It transforms source code into the machine readable code by converting it line by line.
Assembler – It converts assembly language program into machine language program.
Modem – (Modulator – Demodulator) An electronic device used to convert computer (digital) electronic signals to communication channel (analog) electronic signals and vice-versa.
Cloud Commuting – is the delivery of on-demand computing resources, everything from applications to data centers, over the Internet, e.g. Google.
Dual Core Processor – is the processing technology in which two processors are scheduled together and when one is busy the other takes over.
Internet – It is the worldwide, publically accessible system of interconnected computer networks that transmit data by using the Internet protocol.
Cryptography – It is a method of storing and transmitting data in a particular coded form so that only those can read and process it, for whom it is intended. It includes encoding and decoding of data.