The NP class, or nondeterministic polynomial time, is a category in computational complexity theory that includes decision problems for which a proposed solution can be verified quickly, in polynomial time. This means that if someone gives you a potential solution, you can check its correctness efficiently, even if finding that solution from scratch might be difficult. Problems in NP include famous examples like the traveling salesman problem and boolean satisfiability problem (SAT). While it is easy to verify solutions for these problems, it is not necessarily easy to find them. The relationship between NP and P class—problems that can be solved quickly—is a central question in computer science.