Degree refers to the variations in the intensity or extent of an adjective or adverb.
There are three degrees:
Positive degree: This is the basic form of an adjective or adverb, which does not show any comparison. Example: big, slow
Comparative degree: This shows a comparison between two things, often by adding "er" or using "more" or "less." Example: bigger, slower, more beautiful
Superlative degree: This shows the highest or lowest comparison, often by adding "est" or using "most" or "least." Example: biggest, slowest, most beautiful