A reciprocal is the inverse of a number in terms of multiplication. For a non-zero number ( x ), its reciprocal is ( \frac{1}{x} ). When a number is multiplied by its reciprocal, the result is always 1. For example, the reciprocal of 4 is ( \frac{1}{4} ), since ( 4 \times \frac{1}{4} = 1 ).