A lever consists of a bar that pivots on a fixed point, called a fulcrum. Levers are used to apply force to a load. Examples include hammers, rake, crowbar, baseball bat, etc.
An inclined plane is a simple machine that is a straight, slanted surface. Ramps, ladders, and slides are all examples of inclined planes.
A wedge is a device that is thick at one end and tapers to a thin edge at the other end. A wedge can be thought of as two inclined planes together. In a wedge, the object does not move along the inclined plane. Instead, the plane moves.
A screw can be thought of as an inclined plane wrapped around a cylinder. This spiral inclined plane forms the thread of the screw. Screws, bolts, cork screws, lids of jar, and faucets are all examples of screws.
A pulley is a grooved wheel with a rope, chain, or cable wrapped around it. The pulley is used by pulling on the rope. Blinds, a crane, and a flag pole all work by using pulleys.
A wheel and axle is a simple machine which consists of a large wheel attached to a smaller wheel, called an axle. Examples include a bicycle and a pencil sharpener.