What is the mechanism of Garbage Collector.

 Hi All,

Can anybody please let me know the answers for these questions?

1. What happens (infernally) when Object = Null is made? Is there any difference of making value type variable making it to null?
2. In any program when Garbage collector will get initialized? What is the mechanism of Garbage Collector?
3. In C#.NET, is there any way I can avoid using Sqlcommand to connect to database?
4. What all are the ways we can connect client and server? (if client is n  .NET and server is in Java)
5. How actually .NET code is connected to database (SQL)?

Looking forward to hear from you soon.

Thanks,