Computer science: what is a stub?

Self-tutoring about computer science: the tutor mentions the idea of a stub.

In programming, a stub is a function that, when called, returns a value of the expected type so that the calling function can continue running. Being a stub suggests it may have no working internals except to return the same output regardless of input.

During development of a larger system, stubs can be used to establish connectivity, proof-of-life, etc. Ideally, each stub will eventually be developed so its output depends on its input.

Source:

softwareengineering.stackexchange.com