In your own words, what is TDD about?
TDD, or, Test Driven Development, serves to increase productivity in a project by giving a precise guideline for the codebase to meet, allowing developers to essentially “tick boxes” to meet requirements.
What is a MOCK (also called DOUBLE) and how does it help in unit testing?
A mock is a fake set of data that a test case uses in order to avoid tying up resources and/or modifying a working database.