Q:

What does "authenticate with" mean?

I knew the authenticate means to prove that something is real, true. For example The system need to authenticate the user before the user can use the system.
But I can't understand the below example well. please help to review it.
The sentence I read is from here.

In the traditional client-server authentication model, the client
  requests an access-restricted resource (protected resource) on the
  server by authenticating with the server using the resource owner's
  credentials.

What does authenticate with mean? Thanks.
Does it mean server provide the authenticating function to authenticate the client? Thanks.

A:

"with the server" identifies the server as the controlling authority.
Without a controlling authority in theory, you might simply compare the credentials to copies you have on paper yourself. In most cases, though, the controlling authority is self-evident from the context.

