Comparative: Comparing a smaller quantity, we use the word "fewer". For example, "There are fewer people at the party today than yesterday." It indicates a decrease in the number of people.
Superlative: When referring to the smallest quantity, we use the word "fewest". For instance, "Out of all the candies, she has the fewest."
In both cases, the comparative and superlative forms demonstrate a decrease or minimal quantity when compared to others.
These forms are especially useful when making comparisons and highlighting the smallest number of a particular item or group.