Credentials in System.Net and WSE 3.0

 I saw the following two lines of code: 
1 ws.SetClientCredential(Of UsernameToken)(New UsernameToken(userId, password))
2
3
4 and
5
6 ws.Credentials=System.Net.NetworkCredentials(userid, password)
 The two lines are in quite separate context. Each seems to do what its supposed to - pass the credentials to a web service.
But I think the first uses WSE 3.0 and the latter System.Net. Can someone verify this idea?

...