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The keys can be used individually or in combination with other keys. The keyboard normally
                 contains 101 to 108 keys, which can be classified as follows:

                      ◦ Alphanumeric keys (A-Z, a-z, 0-9)
                      ◦ Control keys (Ctrl, Alt, Esc, etc.)

                      ◦ Function keys (F1-F12)
                      ◦ Special keys (Caps Lock, Backspace, Spacebar, Arrow keys, Home, End, etc.)

                      ◦ Punctuation keys (“ , ” , “-”, ; , etc.)
                 Depending on the position or placement of the keys, the layout of a keyboard comes in various
                 styles such as  QWERTY,  QWERTZ,  AZERTY and  DVORAK.  QWERTY  keyboard  is the  most
                 commonly used keyboard. It is based on the English language. Its name is derived from the
                 sequence in which six alphabetical keys are positioned on the upper line of the keyboard. AZERTY
                 type  keyboard  is mostly used in France  (‘A’ and ‘Z’ characters  replace  ‘Q’ and  ‘W’ on such
                 keyboards). QWERTZ type keyboard is widely used in Germany and Central Europe.

                 •  Mouse: It is a handheld pointing device which is used on a flat surface
                   and is represented by a pointer on the screen. The pointer on the screen
                   moves when the mouse is moved by the user. A mouse generally consists
                   of two buttons and a scroll wheel on its top.  It allows you to put data
                   into a computer by using point, click, and drag and drop commands. It
                   controls the movement of the pointer on the screen. It is used to move and select icons, files,
                   and folders on your computer. There are two main types of mouse: optical and mechanical.
                   An optical mouse is an advanced computer pointing device that uses a light-emitting diode
                    (LED) and an optical sensor. This type of mouse does not require any internal cleaning since
                    there are no rotating parts. However, they can get sticky over time as dust collects near the
                    light emitter. This can cause erratic cursor movement or prevent the mouse from working.
                    You must clean the surface of the mouse and the mouse pad regularly to prevent dust from
                    accumulating on the mouse.

                              A mechanical mouse uses a rubber ball that makes contact with wheels inside the
                               unit when it is rolled on a pad. This type of mouse is especially susceptible to dust
                               and particles that can accumulate inside the mouse, which can make it difficult to
                               track or move properly. If the mouse pointer does not move smoothly, you will
                               have to clean the rubber ball.
                 •  Scanner: A scanner is a device that scans a document by sensing the reflection that is received
                   when the scanner emits rays on the contents. It takes the image of contents and converts it
                   into a digital file.

                    The scanned image or photo can be stored in a computer and easily transferred to a secondary
                   storage device. Scanners can be categorized as ‘Hand held scanner’ and ‘Flatbed scanner’.

                      ◦ Hand-Held Scanner: It is a type of scanner that can be held in hand and
                      rolled over a flat image or document. It is used to scan documents into
                      digital forms. Scanners of this type are small in size, portable and less
                      expensive.


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