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How Does a Computer Work?

A computer is a machine composed of hardware and software components. A computer receives data through an input unit based on the instructions it is given and after it processes the data, it sends it back through an output device.

A computer is an electronic machine that processes information—in other words, an information processor: it takes in raw information (or data) at one end, stores it until it’s ready to work on it, chews and crunches it for a bit, then spits out the results at the other end.

All these processes have a name. Taking in information is called input, storing information is better known as memory (or storage), chewing information is also known as processing, and spitting out results is called output.

Binary and Data:

All computer data is represented using binary, a number system that uses 0s and 1s. Binary digits can be grouped together into bytes.

Computers use binary - the digits 0 and 1 - to store data. A binary digit, or bit, is the smallest unit of data in computing. It is represented by a 0 or a 1. Binary numbers are made up of binary digits (bits), eg the binary number 1001.

The circuits in a computer’s processor are made up of billions of transistors. A transistor is a tiny switch that is activated by the electronic signals it receives. The digits 1 and 0 used in binary reflect the on and off states of a transistor.

Computer programs are sets of instructions. Each instruction is translated into machine code - simple binary codes that activate the CPU. Programmers write computer code and this is converted by a translator into binary instructions that the processor can execute.

All software, music, documents, and any other information that is processed by a computer, is also stored using binary.

Circuits and logic:

Computer circuitry, Complete path or combination of interconnected paths for electron flow in a computer. Computer circuits are binary in concept, having only two possible states. They use on-off switches (transistors) that are electrically opened and closed in nanoseconds and picoseconds (billionths and trillionths of a second). A computer’s speed of operation depends on the design of its circuitry. Faster rates are achieved by shortening the time it takes to open and close the switches and by developing circuit paths that can handle the increased speeds.

Logic design, Basic organization of the circuitry of a digital computer. All digital computers are based on a two-valued logic system—1/0, on/off, yes/no. Computers perform calculations using components called logic gates, which are made up of integrated circuits that receive an input signal, process it, and change it into an output signal. The components of the gates pass or block a clock pulse as it travels through them, and the output bits of the gates control other gates or output the result. There are three basic kinds of logic gates, called “and,” “or,” and “not.” By connecting logic gates together, a device can be constructed that can perform basic arithmetic functions.

CPU and Memory:

Computers require input hardware, processing hardware and output hardware. The hardware that defines a computer is the CPU and memory. Without these a computer could not function.

The CPU and memory work together to run programs.

• CPU - executes programs using the fetch-decode-execute cycle.

• Memory - stores program operations and data while a program is being executed. There are several types of memory, including: registers, cache, RAM and virtual memory.

• Storage - stores programs and files long term, even when they are not in use. Devices such as hard drives, USB memory sticks or SD cards are used to store files.

Hardware and Software:

Quite simply, computer hardware is the physical components that a computer system requires to function. It encompasses everything with a circuit board that operates within a PC or laptop; including the motherboard, graphics card, CPU (Central Processing Unit), ventilation fans, webcam, power supply, and so on.