ftp is the default client implementation of FTP (File Transfer Protocol) on FreeBSD systems. ftp is IPV6 aware, and is capable of creating, deleting, modifying and transferring files to and from remote machines running an FTP server that supports these operations. It is also capable of retrieving files using HTTP (from a "web server").
These days, because the FTP protocol requires two ports (clumsy with firewalls), and cannot support encrypted transactions (it must be wrapped or tunneled in another protocol - also tricky because it requires two ports - see FTPS), many people prefer to use the slower but more secure sftp (an SSH subsystem) or rsync (a remote data synchronization engine with SSH support).
It's worth noting that on modern hardware, SSH transports are only slower than FTP over an extremely fast connection - such as a local network. The slowdowns are not network-related, but CPU-related due to the encryption overhead of the SSH transport - which means that for most of the purposes FTP is traditionally used for, there really isn't any noticeable slowdown at all.
-a don't login, use anonymous login -A force active mode -i no interactive prompts -p force passive mode -P change the port to this -v verbose