concept — A concept is an idea or abstract principle.
idea — any conception existing in the mind as a result of mental understanding, awareness, or activity.
fraction — Mathematics. a number usually expressed in the form a/b. a ratio of algebraic quantities similarly expressed.
part — a portion or division of a whole that is separate or distinct; piece, fragment, fraction, or section; constituent: the rear part of the house; to glue the two parts together.