Users are defined as accounts/people that can access the system in order to handle quotes or adjust settings. Depending on the user level (regular user or administrator user) access to certain areas within the system will be limited.
There is no limit when it comes to the number of users that you are allowed to create and we encourage you to create as many as you need in order to be able to track activity, performance, conversion rates and act on the results you see per-user or as a whole.
Please refer to the question marks for each field when adding/editing users for further details on each field.