What is Input Devices and types?Explain Keyboard?

 Input Devices

• The data is entered directly to the computer and sometimes indirectly.
• In first case,the data goes directly to the computer from the source and in the second case;we have to carry out some intermediate handling.
• In either case the task is to gather data to be processed by the computer.

Types

There are three general types of input devices.

1. Keyboard
2. Pointing devices
3. Source Data entry devices

Keyboard

• The keyboard may look like a typewriter keypad to which some special keys have been added.
• The keys normally available on the keyboard are Numeric,Alphabetic,function and aditional special purpose keys.
• It has some additional keys between the main keypad and the numeric keys,and status lights in the upper right corner.The standard keyboard is also called "QWERTY"which describes the beginning keys in the top row of alphabetic letters.
• There are 101 Enhanced keyboard showing the layout of the various  key groups.

Types

There are 5 types of Keyboard.

1. Alphabet Keys
2. Number Keys
3. Special Keys
4. Function Keys
5. Navigation keys

Alphabet Keys

• There are 26 alphabetic keys(A-Z) same as there in the English Alphabets.

Number Keys

•  In the keyboard 1 through 0 numbers on the top row of the number key,there are 10 number key on the keyboard.
• But if the keyboard also has a numeric keypad(1 to 0),then there are 20 number keys on keyboard.

1. 1(END)__________In some programs,the end key move the cursor to the bottom right corner of the screen.
2. 2(Down Arrow)_______This key move the cursor down one line.
3. 3(Page Down)_______The page Down key advances one full screen while the cursor stays at the same place.
4. 4(Left Arrow)_______This key move the cursor one character to the left.
5. 6(Right Arrow)______This key move the cursor one character to the right.
6. 7(Home)_______In some programs,the Home key move the cursor to the top left corner of the screen.
7. 8(Up Arrow)______This key move the cursor one line up.
8. 9(page up)________The page up key backs up to the previous screen while the stays at the same place.
9. 0(Ins)_______The insert key,when toggle key off,causes keyed characters to override with the existing characters.
10. .(Dell)______The dell key deletes a character,space,or selected text.

Special Keys

There are many special keys on keyboard.

• Ctrl+S(save)
• Ctrl+O(open)
• Ctrl+N(New)
• Ctrl+C(Copy)
• Ctrl+V(Paste)
• Ctrl+X(cut)
• Ctrl+A(Select all)
• Ctrl+Z(Undo)
• Ctrl+Y(Redo)

Function key

• The keys are at the top of the computer keyboard labelled:
• F1,F2,F3,F4,F5,F6,F7,F7,F9,F10,F11,F12.
• The functional keys are an easy way to give certain commands to the computer,which are usually operated by keyboard commands.