What is meant by a 'checked exception' in programming?

A checked exception in programming is a type of exception that the compiler requires to be explicitly handled or declared in the method signature using the throws keyword.

Its purpose is to compel the developer to anticipate error handling that may occur during program execution, such as input-output errors.

Example:

public void readFile(String path) throws IOException {
    FileReader reader = new FileReader(path);
    // reading the file
}

Here, IOException is a checked exception, and the calling method must either handle it within a try-catch block or declare throws further.