The parallel structure refers to the repetition of a chosen grammatical form within a sentence. It uses word, phrases or clauses that are grammatically similar or identical in structure, sound, meaning, or meter, in order to show that the ideas are equally important and to give a certain flow while reading the piece of writing.
The sentence "I enjoy eating and cooking" contains this construction because both "eating" and "cooking" are the same type of word: gerunds.
