For those of you who are curious: there is indeed a difference when we use the following uris as parameters for our FtpWebRequest class:

ftp://server/ParentDirectory

ftp://server/ParentDirectory/ (Note the slash at the end)

Let’s say we want to create a new directory named “new” in "ParentDirectory". With the first uri (without the slash) we issue:

MKD ParentDirectory\new 

And with the slash at the end we issue

CWD ParentDirectory

MKD new

The same model is applicable for all ftp commands that the FtpWebRequest class supports