A decision prblem is a computation problem that can be posed as a yes-no question on a set of inputs, with an infinite set of possible input sets. A method for solving a decision problem is a decision procedure, usually given in the form of an algorithm. Solvable decision problems are called decidable.
Decidable problems are placed in different Complexity Classes depending on the resources required to solve them.
These are distinct from function problems, which can give more complex answers than the boolean options of decision problems.