proxy server types

we are given 12 choices for proxy types
i am familiar with only 1 thru 3 [socks, http]
when do you use the other options [4 thru 13] ?

checkpoint firewall 1
open ftp-host:ftp-port
site ftp-host ftp-port
site ftp-host:ftp-port
site ftp-user@ftp-host ftp-port
site ftp-user@ftp-host:ftp-port
user ftp-user@ftp-host ftp-port
user ftp-user@ftp-host:ftp-port
user ftp-user@ftp-host proxy-user
user proxy-user@ftp-host

thank you