Ever heard about blueprints, brainstorming or templates? If so you do know then that all of those are related on giving an idea, concept and a starting point of something.
We usually use those to make a starting point whenever we are going to code and believe it or not, drawing actually helps you out too.
Here are some examples:
Any expensive acquisition is avoided and the resources will always be released thanks to the replying of the objects that are no longer used
Instance of family classes.
Separates object construction that is attached to the representation
Instance is created of several classes
Class what has one and only one instance that can/will exist.
DESING BASED ON THE STRUCTURAL PATTERNS
Object and Class are based and are the fundamentals of this design type.
- Private Class Data
BEHAVIORAL DESIGN PATTERS
It is oriented to the class objects and of course to the communication between them.