BASIC INTRODUCTION TO COMPUTER TECHNOLOGY

A computer is an electronic device, operating under the control of instructions stored in its own memory that can accept data (input), process the data according to specified rules, produce information (output), and store the information for future use. The computer has functions and any digital carries out five functions and these functions are;
- Take data as input
- Store the data/instruction in its memory and use them when required
- Processes the data and converts it into useful information
- Generates the output
Information processing cycle is a sequence of events consisting of input, processing, storage & output. For a computer to perform useful work, the computer has to receive instructions and data from the outside world. The computer receives data and instructions during the INPUT stage of the information processing cycle. Useful information results when appropriate instructions are applied to data. Applying instructions to data takes place during the PROCESSING stage of the information processing cycle. To avoid having to re-enter data and instructions or reprocess information, computers can save information. Saving information on a computer occurs during the STORAGE phase of the information processing cycle. Saving information on a computer occurs during the Storage phase of the information processing cycle. This is followed by the result in the OUTPUT stage. Computer Processing Cycle is a similar process with similar steps by which data is fed to a computer.
Processing – Performing operations on the data
Once the input is provided the raw data is processed by a suitable or selected processing method. This is the most crucial step as it allows for the processed data in the form of output which will be used further.
Processing is usually done by CPU (Central Processing Unit) in a computer. CPU is the crucial component for getting the operations done
Data processing is an essential part of information processing. Making use of processed information in various decision-making process remains the main purpose of information processing. Processing of complex data obtained from various data sources requires sorting and filtering of data. It might also be merged with existing sources of data so as go to receive a new data set. Further analysis of these data sets helps in decision making and subsequent decisions pertaining to other aspects in a decision-making process. The information being used may form a part of short-term memory or long-term memory of overall process.
All the computers that are developed are not alike rather they have different designs and features. Some computers have very high capacity as well as working speed; however, some are slow. Depending upon the requirements, computers are being developed.
CLASSIFICATION OF COMPUTER
Computers are classified depending upon the internal structure and subsequent features and applicability, computer system is categorized as follows ;
Mainframe Computer
It is high capacity and costly computer. It is largely used by big organizations where many people can use it simultaneously.
Super Computer
This category of computer is the fastest and also very expensive. A typical supercomputer can solve up to ten trillion individual calculations per second.
Workstation Computer
The computer of this category is a high-end and expensive one. It is exclusively made for complex work purpose.

Personal Computer (PC)
It is a low capacity computer developed for single users.
Apple Macintosh (Mac)
It is a sort of personal computer manufactured by Apple company.
Laptop computer (notebook)
It is a handy computer that can be easily carried anywhere.

Tablet and Smartphone
Modern technology has advanced further. It has helped develop computers that are pocket-friendly. Tablets and smartphones are the best examples of such computer.
Special NOTES;
Servers
Server usually refers to a computer that is dedicated to providing one or more services. A server is expected to be reliable (e.g. error-correction of RAM; redundant cooling; self-monitoring, RAID), fit for running for several years, and giving useful diagnosis in case of an error. For even increased security, the server may be mirrored. Many smaller servers are actually personal computers that have been dedicated to provide services for other computers.
- A database server
- A file server does not normally perform computational tasks or run programs on behalf of its client workstations but manage and store a large collection of computer files. The crucial function of a file server is storage. File servers are commonly found in schools and offices, where users use a local area network to connect their client computers and use Network-attached storage (NAS) systems to provide data access. Example; Raspberry pi configured as Local area network Server
- A web server
- A terminal server
Computer Hardware
What are external hardware components?
External hardware components, also called peripheral components, are those items that are often externally connected to the computer to control either input or output functions. These hardware devices are designed to either provide instructions to the software (input) or render results from its execution (output).
Common input hardware components include the following:
Mouse. A mouse is a hand-held pointing device that moves a cursor around a computer screen and enables interaction with objects on the screen. It may be wired or wireless.
Keyboard. A keyboard is an input device featuring a standard QWERTY keyset that enables users to input text, numbers or special characters.
Microphone. A microphone is a device that translates sound waves into electrical signals and supports computer-based audio communications.
Camera. A camera captures visual images and streams them to the computer or through a computer to a network device.
Touchpad. A touchpad is an input device, external or built into a laptop, used to control the pointer on a display screen. It is typically an alternative to an external mouse.
USB flash drive. A USB flash drive is an external, removable storage device that uses flash memory and interfaces with a computer through a USB port.
Memory card. A memory card is a type of portable external storage media, such as a CompactFlash card, used to store media or data files.
What is hardware as a service?
While it's common for individuals or businesses to purchase computer hardware and then periodically replace or upgrade it, they can also lease physical and virtual hardware from a service provider. The provider then becomes responsible for keeping hardware up to date, including its various physical components and the software running on it.
Types of Hardware Function and examples Input devices
- used to insert or supply data to the computer
- examples include the keyboard, mouse and a memory (USB) stick
Processing and
Internal memory devices
- used to process data using program instructions
- examples include the motherboard, CPU (central processing unit) and main memory or RAM (Random Access Memory)
Output devices
- used to display data and programs from the computer
- examples include a computer monitor or screen, and a printer
Storage devices
- used to store programs and data
- examples include the hard disk drive and optical disk drive
QUESTIONS:
Objective Questions
1. An electronic tool that allows information to be input, processed, and output is called _______________.
- Operating system
- Motherboard
- Computer
- CPU
2._____________ is a worldwide network of computers.
A.CPU
- Internet
- RAM
- Network
3. Name the brain of the computer that does the calculation, moving, and processing of information.
- CPU
- RAM
- Motherboard
- Hard Drive
Subjective Questions
1) Explain the main purpose of an operating system?
2)What are the different types of CPU registers in a typical operating system design?