Static type checking is a process used in programming languages to verify the types of variables and expressions at compile time, before the program runs. This helps catch type-related errors early, ensuring that operations on data types are valid. For example, if a variable is declared as an integer, static type checking will prevent it from being assigned a string value. Languages like Java and C++ utilize static type checking to enhance code reliability and maintainability. By enforcing type rules, developers can avoid common bugs and improve the overall quality of their software, making it easier to understand and modify in the future.