Introduction to Computer

 The word "computer" comes from the word "compute", which means "to calculate". Hence, people usually consider a computer to be a calculating device that can perform arithmetic operations at high speed. 

The straightforward meaning of a computer is a machine that can calculate. However, modern computers are not just a calculating device anymore. They can perform a variety of tasks. In simple terms, a computer is a programmable electronic machine used to store, retrieve, and process data.

According to the definition, "A computer is a programmable electronic device that takes data, perform instructed arithmetic and logical operations, and gives the output."

Whatever is given to the computer as input is called 'data', while the output received after processing is called 'information'.

Although the original objective of inventing a computer was to create a fast calculating device, we name define a computer as a device that operates upon data because more than 80% of work done by today's computers is data processing. Data can be anything like bio-data of applicants when computer is used for short listing candidates for recruiting; marks obtained by students in various subjects when used for preparing results; details (name, age, sex, etc.) of passengers when used for making airline or railway reservations; or number of different parameters when used for solving scientific research problems, etc. Notice from examples that data can be either numerical non-numerical, or a mixture of both.  

A computer is often referred to as a data processor because it can store, process and retrieve data whenever desired. The name data processor is more inclusive because modern computers not only compute in the usual sense but also perform other functions with data that flows to end with them. For example, data processors may gather data form various incoming sources, merge(process of mixing or putting together) them all, sort(process of arranging in some sequence - ascending or descending) them in the desired order, and finally print them in desired format. 

A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. A computer system is a "complete" computer that includes the hardware, operating system (main software), and peripheral equipment needed and used for "full" operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster.

A broad range of industrial and consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devices like personal computers and mobile devices like smartphones. Computers power the Internet, which links hundreds of millions of other computers and users.

Early computers were meant to be used only for calculations. Simple manual instruments like the abacus have aided people in doing calculations since ancient times. Early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century. The first digital electronic calculating machines were developed during World War II. The first semiconductor transistors in the late 1940s were followed by the silicon-based MOSFET (MOS transistor) and monolithic integrated circuit (IC) chip technologies in the late 1950s, leading to the microprocessor and the microcomputer revolution in the 1970s. The speed, power and versatility of computers have been increasing dramatically ever since then, with transistor counts increasing at a rapid pace (as predicted by Moore's law), leading to the Digital Revolution during the late 20th to early 21st centuries.

Conventionally, a modern computer consists of at least one processing element, typically a central processing unit (CPU) in the form of a microprocessor, along with some type of computer memory, typically semiconductor memory chips. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices include input devices (keyboards, mice, joystick, etc.), output devices (monitor screens, printers, etc.), and input/output devices that perform both functions (e.g., the 2000s-era touchscreen). Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.