Introducing the power of design patterns

So what is a design pattern? Actually, the phrase design pattern is not associated with any programming language, and also it doesn't provide language-specific solutions to problems. A design pattern is associated with the solution to repetitive problems. For example, if any problem occurs frequently, a solution to that problem has been used effectively. Any non-reusable solution to a problem can't be considered a pattern, but the problem must occur frequently in order to have a reusable solution, and to be considered as a pattern. So a design pattern is a software engineering concept describing recurring solutions to common problems in software design. Design patterns also represent the best practices used by experienced object-oriented software developers.

When you make a design for an application, you should consider all the solutions to common problems, and these solutions are called design patterns. The understanding of design patterns must be...