Post's problem

Post's problem is a question in computability theory that asks: Can we create a general method (or algorithm) to determine if any given computer program will eventually halt (stop running) or run forever? While some programs' behaviors are predictable, there's no universal way to decide for all programs, as some may behave unpredictably. This means there's no perfect, all-encompassing tool to always tell us whether a program will finish or get stuck in an infinite loop. The problem highlights fundamental limits in predicting algorithmic behavior.