For some long I was searching for a good article which explains how to use interface in .Net programming. It is not for a developer who is passionate in programming, got good knowledge in object oriented programming and comes with computer science degree. But for people who came into the field because others compelled and not having computer science background. At some point I thought of writing one myself. But I was able to find a good one. Below are the link(s). I will be updating if I came across another one.