This document discusses different types of software testing and test-driven development. It defines functions and how to pass arguments to functions. It describes assertions as true-false statements to check conditions and preconditions and postconditions to define the expected state before and after code execution. It lists different types of testing including unit testing, integration testing, and regression testing. It explains test-driven development as a process of writing automated tests before code to define desired functions and improvements and repeating testing and coding until passing all tests.