In what situations and for what purposes are annotations used in the Python language?

Annotations in Python are used to specify the types of variables, function parameters, and return values. They help improve code readability and allow static type checking tools (such as mypy) to verify type correctness without executing the program.

Example of using annotations:

def greet(name: str) -> str:
    return f"Hello, {name}!"

Annotations do not affect code execution but serve as documentation and help IDEs and linters identify errors during development.