Degrees of comparison are used to describe the differences in qualities among nouns. There are three degrees: positive, comparative, and superlative. The positive degree describes a quality without comparison, such as tall. The comparative degree compares two nouns, often formed by adding "-er" or using "more," as in taller or more beautiful. The superlative degree expresses the highest degree of a quality among three or more nouns, typically formed by adding "-est" or using "most," as in tallest or most beautiful. These degrees help clarify the extent of a quality in relation to others.