COMPUTER HARDWARE

Computer hardware includes the physical parts of a computer, such as the case,[1] central processing unit (CPU), random access memory (RAM), monitor, mouse, keyboard, computer data storage, graphics card, sound card, speakers and motherboard

Hardware is typically directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system, although other systems exist with only hardware

1. Peripheral devices: 

Are devices outside the central processing unit but under its control, they may be input devices, output devices, such as printers, or storage devices, such as disk drives

2. Accessories devices: 

Are the device that support the proper handling of an electronic device, such as computer. Example, Computer bag, computer stand etc

Example of Computer Hardware

•  Monitor 
• System Unit.
• Mouse
• CPU 
• RAM 
• HDD 
• Speaker 
• NIC.
• Keyboard
• VGA Cable
• Power Cable

Categories of Computer Hardware

Computer hardware can be categorized into five parts namely,

1. Input device
2. Processing device 
3. Output device
4. Storage device 
5. Communication devices

1. Input Devices

Is a Computer component which used to enter data into a Computer system.

Examples; Keyboard, Mouse, Scanner, Digital Camera, Microphone, Touch pads, Joystick, Webcam, Light pen e.t.c

Keyboard

Keyboard is an important device that allows a user to enter text or symbols like letters and numbers into a computer. It is the main input device for most computers

The keys are following

Short Explanation of keyboard keys (Button)

1. ENTER or RETURN - Moves the cursor down one line and to the left margin.
2. DEL or DELETE - Deletes the character at cursor and/or characters to the right of the cursor and all highlighted (or selected) text.
3. BKSP or BACKSPACE - Deletes the character to the left of cursor and all highlighted text. 
4. SPACE BAR - Moves the cursor one space at a time to the right
5. SHIFT KEY - Use the shift keys to type capital letters and to type the upper character on keys with two characters on them
6. CAPS LOCK - Locks the keyboard so it types capital letters (a light goes on when caps lock is on) 
7. TAB - Moves the cursor five spaces to the right(number of spaces are usually adjustable).
8.  ESC or ESCAPE - Cancels a menu or dialog box 
9. ARROW KEYS - Moves the cursor around document without changing text.
10. FUNCTION KEYS or F KEYS - Access commands by themselves or in combination with the three command keys; CTRL, SHIFT, and ALT

The Mouse

Mouse is the pointing device which used to select different object. It has two buttons (left & Right) that control the movement of the cursor.

Left button - used to select menu options or commands by pointing & pressing the button once. 

Right button - used to access shortcut menu within windows and windows application.

Scroll wheel- Used to show the hidden part of the document in different applications, example In MsWord, Ms-Excel.

• Left click: Use your first finger to click the left button once.
• Right click :Use your second finger to click the right button once
• Double click :Use your first finger to click the left mouse button twice quickly
• Drag :Click and hold the left mouse button, move the mouse as necessary then release the left mouse button 
• Scroll wheel :Helps to move up and down a document in some applications

Mouse Actions/Operations

1. Click: Point to the item, then tap (press and release) the left mouse button.
2. Double-click: Point to the item, and tap the left mouse button twice in rapid succession - click-click as fast as you can.
3. Right-click: Point to the item, then tap the mouse button on the right.
4. Point: To point an item means to move the mouse pointer so that it's touching the item. 
5. Drag: Point to an item, then hold down the left mouse button as you move the mouse. To drop the item, release the left mouse button.

2. Processing Devices

These are devices used to process (Convert)raw data into information. In computer system this device is known as Central Processing Unit (CPU)

CPU: Is a main component of the computer, used to process the data fed into the computer to get information that is understood by human.

Processing data may include the following ;

• Calculating
• Sorting
• Searching
• Storing
• Drawing

3. Output devices

These are devices that translate information 

processed by the computer into a form that 

humans can understand.ie are the devices which enables user of computer to get the result of the processed data.

Display the information to the user

Example:

• Monitor
• Printer
• Speakers
• Projector etc

Categories of Output

1. Softcopy:-Is the data that is shown on a display screen or is in audio or voice e g:-Monitor, Speakers etc. 
2. Hardcopy:- Is the printed output e g printer, plotters etc. A printed paper is a good example of Hard copy output. Hard copy:Printed on paper or other permanent media

4. Storage Devices

Are devices used to saves data and programs.

Types of storage devices

• Temporary(Primary) storage devices
• Permanent (Secondary) Storage Devices

Temporary (Primary) storage devices

Is where the information to be processed is held and anything stored in will be lost 

when the power is turned off .

Example: RAM (Random Access Memory)

Permanent(secondary)Storage devices

Is used to hold data and programs permanently regardless whether power supply to computer is on/off, it holds/store information permanently for Future use.

A computer commonly has two types of storage:

Internal and External storage devices.

1. An Internal Storage e.g. Hard Disk Drive (HDD)
2. An external / Removable Storage e.g. Floppy disk, hard disk, magnetic tape, CD-ROM, DVD, Flash disk etc.

5. Communication Devices

Communication devices used for the purpose of Linking/connecting computers together .It includes Network cards, fiber optic cable, coaxial cable, twisted pair ,modem, satellites, switch etc.