Please explain the differences between 'users' and 'mail accounts'.

Please explain the differences between 'users' and 'mail accounts'.

I'm new to zoho and i recently set up a free business email account for a friend. Could you please explain the differences between a 'user' and a 'mail account'? It isn't clear on the website, and searching in the forums, blogs, and on Google hasn't cleared it up at all. I understand the free service allows up to five users, but this seems to be different than accounts. For example, the website describes "users that do not have a mailbox" and on our dashboard page, there are separate areas with info about users and accounts. It is very confusing. Are 'users' actual persons, or are they email addresses that one sets up in order to send and receive mail?