The word pattern means a guide or a model that is to be followed when making things. In software development, we often use programming techniques and solutions developed by others that prove to be credible over time. Solutions to software problems were not developed overnight, and most of these problems were common across the development world, so these time-tested solutions were grouped to be re-used by others.

So a design pattern is a re-usable solution that can be used in our projects so that time-tested programming techniques can be employed to solve similar kinds of problems.

The main difference between architecture and design patterns is that design patterns deal with implementation-level issues, and are more close to the programming and development platform, whereas architecture is at a more abstract level and is independent of the implementation. Design patterns tell us how we can achieve a solution in terms of implementation. But the patterns themselves are independent of the programming language and technology platform. We can implement a particular design pattern in any language we want: JAVA, C# or PHP. We cannot use design patterns as-it-is in our projects. They show us the right path to take in order to solve a problem, but they are not a complete solution. We cannot simply copy-paste a particular design pattern's code directly into our project. We will need to modify it to suit our own unique needs and implementation platform.

In the coming chapters, we will learn some of the famous design and commonly used patterns, with sample code in ASP.NET.