Introduction to Computer Basics
Introduction to Computer Basics
Free Computer Basics Tutorials
You can check the previous part on introduction to computers which is a good guide for beginners.
Types of computers can be classified according to operation principles.
There are three types of computers based on their principles of operation:-
Analog computers – They are used to manipulate analogue data (continuous and uncountable data) for example they are good in dealing with physical variables such as pressure, voltage, temperature, speed, among others. These computers are almost obsolete nowadays.
- Digital Computers – They are specifically designed to work on digital data using the binary numbering system which uses two numbers, 0 and 1 (binary Zero and One). Digital computers are more accurate and faster as compared to analogue computers. They are used widely in the research, business, education, and communication sectors among others. In another simple way, it is a computer that performs logical and mathematical operations with quantities represented as digits, usually in the binary number system.
- Hybrid Computers – These types of computers are usually designed for specialized tasks. Their design is a combination of both analogue and digital computers' best features. The digital part is used as the controller and provides logical and numerical calculations, and on the other hand, the analogue component serves as a solver of differential equations and other complex mathematical equations.
Analog Computing Machine
Types of Computers According to Size and Power
Computers Classified According to Size and Power
Super Computers – They are very fast, most powerful and very expensive computers that we have today in the computing world. They are mainly used for complex works for example in most scientific research stations, weather forecasting stations, space exploration among other places.
Mainframe computers - They are large and powerful computers but not like the supercomputers. They can support hundreds or thousands of users at the same time.
Minicomputers – These are scaled down version of mainframe computers. They can also support up to around 200 users simultaneously.
Micro-computers (personal computers) – These are small computers that are designed to be used by one user at a time, they are then divided into desktops and laptops.
Tianhe-2 in National Supercomputer Center in Guangzhou
Computer Keyboard is an Input Device
As a computer learner, you need to know more about the keyboard and mouse because you will be interacting with them a lot. The keyboard is an input device that will help you enter raw data into your computer. We have different types of keyboards based on their layouts but their mode of operation is basically the same.
The keyboard as an input device contains a number of keys that are pressed in order to enter the desired data into the computer. These keys are arranged in a specific way on your keyboard.
- Typewriter keys (alphabetic keys)
- System keys
- Application key
- Function keys
- Numeric keypad
- Cursor control keys
- Enter keys
The Numeric Keypad
It is positioned on the extreme right-hand side of the keyboard. It contains:-
- Num Lock – For turning on and off the numeric keypad.
- / Forward Slash - Used for calculations dealing with division.
- * The asterisk - Used for multiplication.
- - Subtraction sign – used for difference calculations.
- + Addition sign – used for summing.
- Enter key – Also known as the return key - it is an alternative to clicking on the okay button. Used in a word processor, it will take you one line down.
- Numbers 0 – 9.
- Numeric/Punctuation Keys - These are the series of keys on top of the alphabetical keys.
- Caps lock (for capital letters).
- Tab key (for indenting a paragraph).
- Shift key (Shifts from uppercase characters to the lower case and vice versa and helps us to type the characters on top of any key with two sets of characters.)
- Return key or Enter key (Help us to go to the next paragraph).
- Control key – (ctrl) When pressed with another key, it performs a special operation.
- Alternate key – (alt) Used to change the function of other pressed key and the results will vary depending on the program.
- Backspace - For deleting (erasing) characters to the left of the cursor.
- Spacebar - For creating a space while typing.
- Windows logo key - once pressed it brings out the start menu.
- Page up - For scrolling through pages that are above the current page.
- Page down - for navigating through pages that are down the current page.
The mouse is an an important input device used generally in computers for pointing, clicking and dragging. The most common types of mice have got three buttons.
Terms used while working with the mouse
- Click – Clicking (depressing) the left mouse button once.
- Double click – clicking twice on the mouse left button.
- Triple click – clicking thrice on the left button.
- Right click – clicking on the right mouse button.
- Dragging – clicking and holding on the mouse button.
Left mouse button
- Used to select by clicking once.
- To highlight by clicking, holding down the left button and then dragging on the text you want to select.
- For moving items by clicking, holding on and then dragging them.
- For issuing commands to the computer.
Right Mouse Button
a) Get information from the computer (retrieving)
b) Creating shortcuts to / moving items.
It is usually situated between the right and left button. It is used for scrolling or navigating through an open document.
A USB Computer Mouse
Starting the Computer
For you to be able to use a computer, you must turn it on. The monitor and the system unit of a desktop computer must be turned on. You should be able to locate the power button for both of them. The modern electronic equipment uses the same symbol a zero (0) and a one (1) inserted on it to denote the power on and off button. Just have a look at the symbol on your Mobile's on / off button to get the picture. After locating the power button, turn on the system unit, and then turn on the monitor (there is no particular order, you can start with any). Just press the button in and release it.
Once you power on your computer, you should be able to see some text and graphics appearing on your screen. Be patient and wait for your computer to load/boot/start.
Booting is the process by which the computer loads the system files into the main memory in readiness for use. In simple terms, it is the start-up process of a computer.
Did you learn something from this Introduction to computers?
Introduction to Computers
© 2012 Patrick Kamau