I had asked a related question on Super User:
A use case of a system "receiving" files over FTP would be, for example, the way WordPress plugins are installed via 1-click where WordPress initiates a file transfer to the local Linux box from the remote WordPress plugin repository using ftp(s)
More specifically this screen:
My initial understanding that WordPress would transfer the files from the WordPress plugin repository, like how a FTP client would do. But further discussions on chat have left me confused as to why would WordPress require the FTP details of the web server?
What am I missing here?