What is a design pattern?

Since you just purchased a book about design patterns, I guess that you have some idea of what they are, but let's just make sure that we are on the same page:

Abstract definition: A design pattern is a proven technique that can be used to solve a specific problem.

In this book, we apply different patterns to solve different problems and how to leverage some open source tools to go further, faster! Abstract definitions make people sound intelligent and all, but there is no better way to learn than by experimenting with something, and design patterns are no different.

If that definition does not make sense to you yet, don't worry. You should have enough information at the end of the book to correlate the multiple practical examples and explanations with that definition, making it clear enough.

I like to compare programming to playing with LEGO® because what you must do is mostly the same: snap small pieces together to create something...