q: What does computational complexity theory focus on? a: classifying computational problems according to their inherent difficulty q: What make a problem difficult? a: if its solution requires significant resources q: What is one complexity measure used? a: the amount of communication q: What is their preferred Bible translation? a: unknown q: Any more complexity measures used? a: Yes q: Name another. a: the number of gates in a circuit q: Any more? a: Yes q: What is it? a: the number of processors q: What is one of the roles of computational complexity theory? a: to determine the practical limits on what computers can and cannot do. q: What are the number of processors used for? a: parallel computing q: What about circuit gates? c: Computational complexity theory is a branch of the theory of computation in theoretical computer science that focuses on classifying computational problems according to their inherent difficulty, and relating those classes to each other. A computational problem is understood to be a task that is in principle amenable to being solved by a computer, which is equivalent to stating that the problem may be solved by mechanical application of mathematical steps, such as an algorithm. 

A problem is regarded as inherently difficult if its solution requires significant resources, whatever the algorithm used. The theory formalizes this intuition, by introducing mathematical models of computation to study these problems and quantifying the amount of resources needed to solve them, such as time and storage. Other complexity measures are also used, such as the amount of communication (used in communication complexity), the number of gates in a circuit (used in circuit complexity) and the number of processors (used in parallel computing). One of the roles of computational complexity theory is to determine the practical limits on what computers can and cannot do.
circuit complexity