Developer.com: PHP Pattern Principles Oct 17, 2005, 10 :00 UTC (0 Talkback[s]) (6578 reads) (Other stories by Matt Zandstra)
"Although design patterns simply describe solutions to problems, they tend to emphasize solutions that promote reusability and flexibility. To achieve this, they manifest some key object-oriented design principles.
"This article will cover
"Composition: How to use object aggregation to achieve greater flexibility than you could with inheritance alone
"Decoupling: How to reduce dependency between elements in a system
"The power of the interface: Patterns and polymorphism..."