Session Variables & C# Casting

[Rajesh Abraham]

I am new to Asp world and I have a doubt as follows. I
have a class called objTranslator, which I declare and
initiate global.asax as follows.

Session_Start
csTranslator.objTranslator sesObjTranslator= new
objTranslator();
Session["sesTranslator"]=sesObjTranslator;
----------------
Now in WebForm

private csTranslator.objTranslator webTranslator;

In Page Load

if(Session["sesTranslator"]!=null)
webTranslator=(objTranslator)Session["sesTranslator"];

The question is why do I have to explictly cast the
session variable sesTransilator to objTransilator while it
is holding a reference to sesObjTranslator.

So actually what type is the session variable.

In VB.Net one can directly use

webTranslator=Session("sesTranslator")

What is the difference here?

Thanks,

Rajesh Abraham Chacko