The difference between adjective and adverb can be drawn clearly on the following grounds
1. In grammar, the adjective is among the eight parts of speech which identifies and describes a noun or a pronoun, i.e. person, place, animal or thing. As against, an adverb is also one of the parts of speech, which gives you further information about a verb, adjective or any other adverb.
2. While an adjective qualifies a noun or pronoun, the adverb is used to modify the verb, clause, phrase, adjective, preposition and conjunction.
3. Adjective provides answers to questions such as which, how many, what kind, etc. As against, adverbs will answer the questions like how, when, where, how much, how often, to what extent etc.