How does a file get uploded to the server when I give its URL?

[maytan1]

I just wanted to when I upload a file on my server through an online FTP and I give the file's link as http://example.com/img.jpg in the file name column, what does actually happen? The image/file directly gets transferred to the server or first it gets downloaded on local disk and then gets uploaded. Help me out guys.

 

[Cromewell]

In that case web based ftp (most likely) just issues an HTTP GET command to the remote file. It essentially grabs the file the same way you would if you typed in the URL to the address bar on your browser.