Table of Contents The notation of complexity analysis Formal Definition of Asymptotic Notation Common Functions The notation of complexity analysis $O$-notation $O$-notation, often referred to as “Big Oh” notation, describes an upper bound on the behavior of a function. It really means that the function will not grow faster than the a given rate. This rate is typically the highest-order term in the function, and is often referred to as the “dominant term” or “dominant function”.