Simple Machines is divided into 6 kind, that is Lever, Pulley, Wheel and axle, Inclined plane, Wedge, Screw, and Gears.

      Lever is divided in 3 classes. First class, second class, and the third class. The first class lever is a lever which the fulcrum is located between the load and the force. 

Example :
- Seesaw.
- Bicycle hand brakes.
- Hammer's claw.

The second class is a lever which the load is located between force and fulcrum.
Example :
- Wheelbarrow.
- Bottle opener.
- Oars.

The third class is a lever which the force is located between load and fulcrum.
Example :
- Baseball bat.
- Broom.
- Shovel.

There are 3 kinds of pulley , that are constant pulley, released pulley, and complex pulley.
Constant pulley is pulley that works with changing force direction.

Released pulley is a pulley that can move and share the weight in rope.

Complex pulley is a pulley with a federation of released pulley and constant pulley.

Wheel and axle is used by steer and water reel.

Inclined plane is a slope surface that helps people.

All screw is helical inclined plane. Screw comes with different kind of size and shape.

Wedge is simple machine to separate two objects.