[Announcement: Thanks for your interest in C# Basics.A totally modified, updated and enlarged version of the book "Interactive C#" is about to be published.Author recommends this modified and enlarged version for you.]This book is for those who believe that they have learned the fundamentals of C#. Before entering into a topic,author will provide you the basic theory first for your immediate reference and then he will introduce the questions for you.All of these questions will have their own significance. Some of them may seem to be very easy for you, some of them may seem to be very much challenging for you.But in all cases, when you will go through these questions and their respective answers, your knowledge will be either refreshed or enhanced .These knowledge will boost up your confidence level into a new height and at the same time , you will fall in love with this extremely powerful language.Some of these questions are like this: for the entry point of our program we need a Main method in our program-All C# programmers need to know this.Now the question is :Can we have multiple Main method in our program?If your answer is yes then how you will implement that.Take another simple question: We know,C# has many similarities with Java. So,can you point out some of the dissimilarities with it.Or value type and Reference Type are the two most fundamental concepts in this language and we claim class is a reference type and struct is a value type.But Can you prove that with their definitions? How a C# method can return multiple values and many more questions like this. The earlier two design pattern books (Design Patterns in C# and Design Patterns by JAVA) were the true motivation for Author to introduce this new book on C#.