What are simple machines and what is a fulcrum. first class lever second and third lever

A Simple Machine is the Basic Device/Part of any Major Physically Operated System, and is a Machine based on Force Input and Output. Simple Machines are 5 machines that are lone, These 5 Simple Machines are an Inclined Plane, A Screw, Wheel and Axle, Pulley, and a Wedge.
And a Fulcrum is the point the Lever rests on and/or is Basically the Base of the Lever, like a Seesaw for Example.

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion