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.