Component Programming Concepts in ASP.NET

Component based programming has one major advantage that it allows your
code to be more organized, consistent and reusable. A component, in its
simplest form, may be defined as one or more classes that are compiled
into a separate DLL assembly file. You can use these components in one
application or share between multiple applications, the best part of
using component is encapsulation, which means all the massy part of your
class will be hidden to user but all the features your code requires.