basically they are totaly different.
in dotnet everything is an object based.
main feature = .net framework.
.net framework starts new concept for programmers.
.net doesn't compile program into exe files like java. .net programs requires .net framework to run. it is possible but not now, .net framework may port to linux or mac!
"dotnet version vc++ " is an update for older versions of vc++
c# is new language.
vb.net is also new language but based on vb6. if you know vb6, it is very easy to learn vb.net
asp.net, java.net are new languages like vb.net.
microsoft says .net is "new age" for programming and windows platform.
it is difficult to answer this question. it may be better to answer what are same, not different...
are you a programmer? if yes, goto google ask this question there. you will find articles to try answer this topic.
but, still, VB.net is VB, ASP.net is ASP and so on