The simplest way to authorize your friends or colleagues to work with particular directories of your account is to create FTP subaccounts (users).
An FTP subaccount is a combination of a username and a password, which gives
full FTP permissions to a single directory, without giving access to the root
directory, other directories or the control panel. No dedicated IP is required
for FTP subaccounts. Although each FTP subaccount has a login which is different
from yours, both have the same ID in the system.