403 forbidden error

I am trying to remote upload from HTTP site. I can download the files to my computer just fine, but when using remote upload from hosting I get failed files and 403 forbidden error.
Does that mean the HTTP site blocked the option of remote uploading?
Answer #1
It can be a sign of many things. They most probably are blocking automated downloading.
Answer #2
Remote upload is different than me downloading to my PC?
Answer #3
If I remote upload from site x to y: I’m effectively making the site y downloading from site x. So no, it’s not different from a download, the thing different is that you let another site download it instead of you.