Definition
Left-hand rule is a mnemonic used in physics to determine the direction of force on a current-carrying conductor in a magnetic field

Thumb -: Your thumb represents the direction of the force acting on a current-carrying conductor placed in a magnetic field
Index Finger -: Your index finger represents the magnetic field from north to south
Middle Finger -: The middle finger represents the current from positive to negative
Motor Effect
When a current-carrying conductor is placed in a magnetic field, it experiences a force due to the interaction between the magnetic field and the electric current. This is called the motor effect.
A magnetic field (B) exerts a force on moving electric charges (like electrons in the current).
Magnetic Field
A magnetic field is the region around a magnet or a current-carrying wire where magnetic forces can be felt.
Example -: A wire with electricity running through it can be a example of magnetic field
Current
Electric current is the flow of electric charge (usually electrons) through a conductor, like a wire.