In computer science and mathematics, a problem is considered "decidable" if there exists an algorithm that can provide a correct yes or no answer for every possible input in a finite amount of time. This means that for any instance of the problem, the algorithm will eventually reach a conclusion, allowing us to determine whether the statement or question posed is true or false. An example of a decidable problem is determining whether a given number is even or odd. In contrast, some problems, like the Halting Problem, are undecidable, meaning no algorithm can solve them for all possible inputs. Understanding decidability helps in classifying problems based on their solvability.