The six simple machines are the wheel and axle, lever, pulley, wedge, inclined plane and screw. Simple machines provide a mechanical advantage. This means less force is required to perform work on an object, and the force is exerted over a longer distance, according to TeachEngineering.
The wheel and axle reduces the amount of effort needed for one object to move another. A basic wheel rotates around a stabilizing rod, but more complex forms are found in gears, vehicle wheels and merry-go-rounds, according to Science Trek.
Levers use a pivoting platform to lift heavy objects. Force is exerted on the end opposite the object, so work is distributed across the entire lever. Common examples include hinges, bottle openers and crowbars.
Pulleys conveniently alter a force's direction using a rope and wheel system. For example, a person raising a flag on a flagpole pulls the rope downward using minimal effort, and the pulley's mechanism supports the flag's weight as it travels upward, TeachEngineering states.
Wedges apply pressure to an object's surface to push sections apart. In everyday life, people use nails, zippers, chisels, knives and doorstops as wedges.
An inclined plane is a tilted surface that lets people move an object to a higher or lower position without lifting it, Science Trek states. Ramps, slides and escalators are simple and complex forms of inclined planes.
Screws combine a winding inclined plane with a central rod, allowing an object to change position by moving in a circular motion. Light bulbs and bottle caps are locked into position using a screw mechanism.