Operational semantics is a formal method used in computer science to define the behavior of programming languages. It describes how the execution of a program progresses through a series of state changes, focusing on the operations that take place during execution. This approach provides a clear and precise way to understand how different constructs in a language, such as loops and conditionals, affect the program's state. In operational semantics, the meaning of a program is defined in terms of its execution on an abstract machine. This machine simulates the steps taken by the program, allowing for a detailed analysis of its behavior. By using this framework, researchers and developers can reason about program correctness and optimize language implementations, making it a valuable tool in the field of theoretical computer science.