Every PC user needs a number of input devices to allow them to interact with the PC the most commonly used are the mouse and keyboard others include scanners and graphics tablets. Joysticks and Gaming pads are also known as input devices.
Allows us to navigate around our systems easily. The standard mice are the ones with a ball and roller system. This are fine the only drawbacks can be they can collect dirt and grime and require cleaning.
Optical Mice are now pretty standard. As with all mice they come in various colours and sizes, instead of a ball and roller. They work by shining a light beam onto the desk or mouse mat surface.
Trackball - these use a ball mounted on the mouse unit these allow your hand to mould round the unit and use your thumb or finger to move a marble or ball to move the pointer around the screen.
Cordless/Wireless - Instead of using the normal cable method, these normally use either infa-red or Bluetooth. The PC has a receiver connected via USB with the mouse housing a transmitter. These allow for greater freedom and can be operated from a distance.
These are traditionally corded although many are now moving towards being cordless.
These can include many programmable buttons which you can setup for bookmarks or to launch favourite programs.
PS/2 & USB - The standard way with corded mice or keyboards is to use the PS/2 or USB connectors. As the mice and keyboards don't need to use the transfer rates of USB you can use a USB to PS/2 adapter which allows you to save a USB port and use the PS/2 connector instead.
Wireless and cordless devices typically use a USB receiver device to pickup the signal from the mouse or keyboard and relay it through the PC.