Do we need to create our own classes?

Although the classes provided by the .NET Framework helps us to create web pages and use various other features like data access, sometimes, we may need our own classes. One such example is when we write the business logic of our program. The .NET framework classes help us in data access. But how we process that data and present it to the user of our application is entirely up to us. This is commonly known as the business logic. We can create a custom class for this and store it inside a namespace created by us. We can then use this class in our application by including the namespace in our code. Also, if some other developer is developing a similar application, our class can be used with little or no modification. Our class can be extended to add more features into it. This will save a lot of coding and testing time.