The teacher begins by explaining the concept of methods as encapsulated actions or behaviors within a class. Using practical examples, the teacher demonstrates the syntax and structure of method definitions, illustrating how methods are invoked on objects. Students learn about different types of methods, including those that perform actions (void methods) and those that return values (return type methods). The teacher explains how parameters are passed to methods, highlighting the importance of parameter types and order. Through guided coding exercises, students practice defining methods with various parameter and return types, and invoking these methods on object instances. They explore scenarios where methods perform actions, modify object states, or return specific values, solidifying their understanding of method functionality within a class.