A design pattern is a general reusable solution to a commonly occurring problem in software design.
In software engineering, a software design pattern is a general, reusable solution to a commonly occurring problem within a given context in software design. It is not a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations.
Design patterns are formalized practices a programmer can use to solve common problems when designing an application or system.