Template Method

• Defer the exact steps of an algorithm to a subclass
• Define the skeleton of an algorithm in an operation, deferring some steps to subclasses
• Let subclasses redefine certain steps of an algorithm without changing the algorithm's structure

AbstractClass

• Defines abstract primitive operations that concrete subclasses define to implement steps of an algorithm
• Implements a template method defining the skeleton of an algorithm
• The template method calls primitive operations as well as operations defined in AbstractClass or those of other objects

ConcreteClass

• Implements the primitive operations ot carry out subclass-specific steps of the algorithm