Computer

Computer

A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of operations, called a program, make computers very flexible and useful. Such computers are used as control systems for a very wide variety of industrial and consumer devices. This includes simple special purpose devices like microwave ovens and remote controls, factory devices such as industrial robots and computer assisted design, but also in general purpose devices like personal computer and mobile device such as smart phones. The Internet is run on computers and it connects millions of other computers .Computer is a electronic machine which we use process data into useful information.Computer process raw data into useful data (information).

Information Technology (IT)

Information Technology (IT)

Information technology (IT) is the application of computers and internet to store, retrieve, transmit, and manipulate data,or information, often in the context of a business or other enterprise. IT is considered a subset of information and communications technology (ICT). In 2012, Zuppo proposed an ICT hierarchy where each hierarchy level "contain some degree of commonality in that they are related to technologies that facilitate the transfer of information and various types of electronically mediated communications." Business/IT was one level of the ICT hierarchy.

The term is commonly used as a synonym for computers and computer networks, but it also encompasses other information distribution technologies such as television and telephones. Several industries are associated with information technology, including computer hardware, software, electronics, semiconductors, internet, telecom equipment, engineering, healthcare, e-commerce, and computer services.

Humans have been storing, retrieving, manipulating, and communicating information since the Sumerians in Mesopotamia developed writing in about 3000 BC, but the term information technology in its modern sense first appeared in a 1958 article published in the Harvard Business Review; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for processing, the application of statistical and mathematical methods to decision-making, and the simulation of higher-order thinking through computer programs.

Based on the storage and processing technologies employed, it is possible to distinguish four distinct phases of IT development: pre-mechanical (3000 BC – 1450 AD), mechanical (1450–1840), electromechanical (1840–1940), electronic (1940–present),and moreover, IT as a service. This article focuses on the most recent period (electronic), which began in about 1940.

Main memory

Main memory

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Main memory

Main memory

The computer can manipulate only data that is in main memory. Therefore, every program you execute and every file you access must be copied from a storage device into main memory.

Main memory are two types. Types are following. 

1. ROM(Read only memory)
2. RAM(Random access memory)

1. ROM

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               ROM stand for read only memory .ROM is a type of storage medium that permanently stores data on personal computers (PCs) and other electronic devices. It contains the programming needed to start a PC, which is essential for boot-up; it performs major input/output tasks and holds programs or software instructions.

The types of ROM are following.

1. EROM
2. EPROM
3. EEPROM
4. FLASH EEPROM

2. RAM

              RAM stand for random access memory . RAM  is the place in a computing device where the operating system (OS), application programs and data in current use are kept so they can be quickly reached by the device's processor. RAM is much faster to read from and write to than other kinds of storage in a computer, such as a hard disk drive (HDD), solid-state drive (SSD) or optical drive. Data remains in RAM as long as the computer is running. When the computer is turned off, RAM loses its data. When the computer is turned on again, the OS and other files are once again loaded into RAM, usually from an HDD or SSD .

The types of RAM are following.

1. STATIC RAM
2. DYNAMIC RAM

Central Processing Unit(CPU)

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Central Processing Unit(CPU)

The CPU (Central Processing Unit) is the part of a  computer system that is commonly referred to as the "brains" of a computer. The CPU is also known as the processor (intel) or microprocessor (AMD). The CPU is responsible for executing a sequence of stored instructions called a program.

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CPU is the electronic machine within a computer that carries out the instruction of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. The term has been used in the computer industry at least since the early 1960s .Traditionally, the term CPU refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry