A mock exists in the workspace where it is created.
If you create a mock in a team workspace, then your teammates can see the mock in the Postman app or dashboard under the team workspace.
If you create a mock in a personal workspace, then your teammates won’t be able to see the mock at all
If you create a mock in a workspace, and then share the associated collection to a team workspace, then the mock remains in the original workspace where it was created. So you and your teammates won’t see any mock in the second workspace.
Note that there’s a difference between seeing the mock in the Postman interface and being able to use it. The scenarios described above are how your teammates (and you) can see the mocks.
To use them, all mocks are public (by default) and can be used by anyone. If you check the box to make the endpoint private when you’re creating the new mock, it can then only be accessed with a valid API key.