This document defines and discusses hypotheses. It begins by defining a hypothesis as an assumption made based on evidence that serves as the starting point for an investigation. It then outlines the key characteristics of hypotheses and different types of hypotheses, including simple, complex, directional, non-directional, null, and associative/causal hypotheses. Examples are provided for each type. The document concludes by explaining the functions of hypotheses and how they help in the scientific method.