Faulty parallelism occurs when unequal structures are used to express equal ideas.
Words, phrases, and clauses must all be parallel when they express a similar idea and perform a similar function in a sentence. I like to swim, to read, and to play tennis. I like swimming, reading, and playing tennis. Steve hoped to find tickets to the concert and to take the day off work. We found the ballet to be colorful, exciting and it was beautifully performed.