What are design patterns?

Design patterns are basically best practices in software engineering using object-oriented design (OOD) that describe general reusable solutions to common problems in software design within a given context. These are not the finished or final designs readily transformed into live software product but a description or a template of how to solve a given problem that can be used in many different situations. Design patterns are formalized best practices that can be used to solve common problems when designing a solution.