hello, can any one tell me the difference between vb.net web apps and c# .net webapps y most of the apps are done in c# rather than vb.net
Nothing but preference. C# and VB.Net are extremely similar in nature as far as programming languages go.
Microsoft has said that both languages will co-evolve from now on. They will both get the same additional features with each new release, and MS is committed to both. There was a rumor that VB was going to be replaced by C#, but that is not true. They have dispelled that myth.
Because there are more coders that use c#, perhaps? Underlying philosophy of .net is that you can use language that you are most comfortable with, and stay in the same environment.
The only difference is the language that the code behind files are written in.
Both use the same objects and .NET framework, it's only a choice of programming language.
As for why most examples are in C#, more people prefer to use that.
From what I've heard, VB.NET was shoehorned into .NET as a late addition because too many programmers were familiar with it. Programmers tend to have their preferences with higher-level languages (which is by far the most distinct difference). In the end, they both provide virtually the same capability and functionality.