What is the different between these rsync command

[Matt McCutchen]

On 9/7/07, Yue Davis <davisyue at gmail.com> wrote:
> I would like to know why attempt one and two's result looks identical? For
> attempt two without the "-e ssh" how secure is rsync transferring the data?
> Is it ssh or just plain binary or ASCII transfer?

The first two commands do exactly the same thing because the
destination has a single colon, indicating rsync over a remote shell,
and the default remote shell is ssh.  All "-e ssh" does in this
situation is explicitly restate the default.  (If the source or
destination is an rsync daemon, "-e ssh" does make a difference: it
indicates a single-use daemon invoked over ssh.)

Matt