About Computers

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A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of operations, called programs. These programs enable computers to perform an extremely wide range of tasks.

Computers are used as control systems for a 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-aided design, and also general purpose devices like personal computers and mobile devices such as smartphones.

Early computers were only conceived as calculating devices. Since ancient times, simple manual devices like the abacus aided people in doing calculations. 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 speed, power, and versatility of computers have been increasing dramatically ever since then.

Conventionally, a modern computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to the 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.

Characteristics of Computer:

Computer became very popular and more important part, the unavoidable device of today's world because of its characters like correct and dependable outputs, high speed, accuracy etc. Following are the characteristics of the computer:

1. High Speed

Computer devices, nowadays, works at an amazing speed that we can't even imagine. It works so fast as it works using electric signals which run like light-speed. Computers can do billions of calculations in a second. If the smallest unit of time for humans is a second, computers work by the followings

     a) 1 millisecond = 10-3 or 1/1000 seconds

     b) 1 microsecond = 10-6 or 1/1000000 seconds

     c) 1 nanosecond = 10-9 or 1/1000000000 seconds

     d) 1 picosecond = 10-12 or 1/1000000000000 seconds

2. Reliability

Though computers work this fast, they still provide reliable outputs. Today's technology enables computers to execute billions of tasks in seconds. However, to get the correct output, the input has to be correct too. The output from a computer is so reliable that if the output is unexpected then it is called, "Garbage in, Garbage out".

3. Accuracy 

Computers can perform floating point operation to so many decimal points that the accuracy is beyond expected.

4. Diligence

A computer is a machine, not a living being, it never gets tired. Simply, it can also keep repeating the same task as many times as it is asked too.

6. Memory

While the computer has storage to store user's data (mostly), it also comes with memory (both volatile and non-volatile) which is used by the computer itself to work fast. Memory devices are expensive than storage, thus through a computer, these days can work with nearly 256 GB of memories, most computers come with 8 GB to 16 GB of RAM (volatile memory) or Primary Memory. The computer also includes ROM (non-volatile), and Cache memories of different levels and register memories. Among these, mostly the RAM is expandable.

7. No Logical Decision

The computer can't think and take the decision itself. But computer programs can be written in a way so that it takes logical decisions. Still, it is just the program written by humans, executed by the computer.

8. No IQ

The computer has speed, memory, accuracy but it can not work itself. If not being instructed to do a thing, the computer is nothing but a useless machine. All its hardware power depends on coded instruction to perform their action. Thus it has no IQ

9. Versatility

The computer is not only in use to calculate numeric values. The computer is in use in medical, scientific experiments, multimedia works etc. Computers cover mostly every area we can think of, nowadays.

10. Automation

Computer programs can schedule tasks that a computer can execute without any interaction. Computer programs can also store procedures which computers can execute one after another, again and again.