Please list the relationship and the difference between adverbials and adverbs.

Please list the relationship and the difference between adverbials and adverbs.

Adverbials are closely related to adverbs, because adverb is the principal form of its realization. However, adverbials are far more heterogeneous. Simply put, adverbials and adverbs are similar but not the same. An adverbial is a sentence element or functional category, a part of a sentence performing a certain function. An adverb, however, is a type of word or part of speech. That is to say, an adverb may serve as an adverbial, but an adverbial is not necessarily an adverb. In other words, adverbials can take a variety of forms other than adverbs on different grammatical levels. They can be adjectives or nouns; they can be prepositional phrases, adverb phrases, adjective phrases; or they can be clauses, finite or non-finite.