What are the differences between user and agent?

Live demo is available here: http://real-estate.iwinter.com.hr/index.php/frontend/login/en

Agent can be registered here (not public visible link): http://real-estate.iwinter.com.hr/index.php/admin/user/register

AGENT account is Backend agent, because using Backend part of design and security check.

USER account is also Frontend agent, because using Frontend part of design and security check.

AGENT username: agent
AGENT password: agent

USER username: user
USER password: user

Main differences:

AGENT is person of trust from company, login to backend, they don’t need wait to approve submission, and can set all options/fields of property, for example also badget (new, hot, top etc…)

USER is person not of trust, login only to frontend, need wait to approve submission from admin, and can’t set all propertiy options/fields, for example badget is not available.
Agents outside your company also should have that rule.

You want selection user/agent on frontend on registration (only available in real estate agency portal)?

This is not suggested, but if you really want, in cms_config.php add:

$config['dropdown_register_enabled'] = FALSE;