Computer: an electronic device that operates (works) under the control of programs stored in its own memory unit. A computer is an electrical machine that processes raw data to give information as output. An electronic device that accepts data as input, and transforms it under the influence of a set of special instructions called Programs, to produce the desired output (referred to as Information).

 Explanations;

A computer is described as an electronic device because it is made up of electronic components and uses electric energy (such as electricity) to function. Information and instructions are stored in a computer's internal memory awaiting processing, and the intermediate result (information) is also held before it is communicated to recipients through output devices. The data is processed based on the instructions given. This means the computer is unable to do anything useful on its own. It can only work as per the set of instructions issued. A computer will accept data in one form and produce it in another form. The data is normally held in the computer as it is being processed.

Program: A computer program is a set of related instructions written in the language of the computer & is used to make the computer perform a specific task (or, to direct the computer on what to do). A set of related instructions that specify how the data is to be processed. A set of instructions used to guide a computer through a process.

Data: This is a collection of raw facts, figures, or instructions that do not have much meaning for the user. Data may be in the form of numbers, alphabets/letters, or symbols, and can be processed to produce information.

TYPES OF DATA.

There are two types of data:

Digital (discrete) data: Digital data is discrete in nature. It must be represented in the form of numbers, alphabets, or symbols for it to be processed by a computer. Digital data is obtained by counting.

Analogue (continuous) data: Analogue data is continuous in nature. It must be physically represented to be processed by a computer. Analog data is obtained by measurement. E.g. Pressure, Temperature, Humidity, Length or currents, etc. The output is in the form of smooth graphs from which the data can be read.

Data Processing: It is the process of collecting all items of data together & converting them into information.

The term processing refers to the way in which data is manipulated (or handled) to make it into information. Calculations, comparisons, or any other logic may be used to obtain the result. The processing of data usually results in some meaningful information being produced.

The data has been refined, summarized & manipulated in the way that you want it, or in a more meaningful form for decision-making. The information must be accurate, timely, complete, and relevant.

Characteristics / Features of a Computer.

 Before the 20th century, most information was processed manually or by the use of simple machines. Today, millions of people use computers in offices and at home to produce and store all types of information.

 The following are some of the attributes that make computers widely accepted & used in day-to-day activities in our society:

1. Speed.

A computer's speed allows it to perform a wide range of tasks very quickly. They can perform much more complicated tasks much faster than anyone else. The speed of a computer is measured in.

Millisecond – a thousandth of a second (10-3)

Microsecond—a millionth of a second (10-6)

Nanosecond—a thousand millionth of a second (10-9)

Microsecond—a million millionth of a second (10-12)

2. Accuracy:

Unlike humans, computers are very accurate, so they never make a mistake. A computer can work for very long periods without doing anything wrong. However, when an error occurs the computer has several in-built, self-checking features in its electronic components that can detect & correct such errors.

3. Reliability:

The computer can be relied upon to produce the correct answer if it is given the correct instructions & supplied with the correct data.

4. Consistency:

Computers are usually consistent. This means that, given the same data & the same instructions, they will produce the same answer every time that particular process is repeated.

5. Storage:

A computer can store a large amount of information in a small space. It is possible for a computer to store data & instructions for later use and to retrieve/produce this data when needed by the user.

6. Diligence:

Unlike humans, computers can work continuously without getting tired or bored. Even if it has to do a million calculations, it will do the last one with the same speed and accuracy as the first one.

7. Automation:

 Automated devices, such as computers, perform tasks automatically. Upon receiving instructions, it is guided by them and can carry out its job automatically until it is completed. It can also perform a variety of jobs as long as there is a well-defined procedure.

8. Imposition of a formal approach to working methods:

Because a computer can only work with a strict set of instructions, it identifies and imposes rigid rules for dealing with the data it is given to process.