1st Class LEVER:
Fulcrum (pivot) is in the middle.
Mechanical advantage can be less than 1, equal to 1 or greater than 1
Changes direction of input force (effort)

Examples: Seesaw, crowbar, scissors, pliers
hammer removing a nail

2nd Class LEVER (it is a force multiplier lever)
The load (resistance) (weight) is in the middle.
Mechanical advantage is ALWAYS greater than 1
Does NOT change direction of force.

Examples: nutcracker, bottle opener
wheelbarrow

3rd Class LEVER (it is a speed multiplier lever)
The effort (energy or force or power) is in the middle.
Mechanical advantage is ALWAYS less than 1
Does NOT change direction of force.

Examples: broom, hoe, baseball bat, jaw, bow and arrow, tongs, tweezers, stapler, steam shovel
the hammer (when nailing) your elbow is the fulcrum / your hand is the effort / and the hammer head is the resistance