The main difference between synonyms and antonyms is that they are synonyms with similar meanings, while antonyms are synonyms with similar meanings.
Basically, a dictionary contradicts the opposite. It is very important to know the synonyms and antonyms for words when learning a language. In particular, they help us to expand our vocabulary and to avoid repetition in our writing and speech. In addition, dictionaries and thesaurus often help us to find synonyms and antonyms.