The Role object represents a role of a User.

The User object represents a User.

Groups are a collection of users in the source application. In some applications, they might also be called Teams.

Comments represent the communication happening on a Ticket, both between a User and a Contact and the internal things like notes, private comments, etc. A Ticket can have one or more Comments.

Contact represent the external people you are in contact with. These could be customers, leads, etc. Contacts can be associated with an Account if the underlying product supports it.

Tags represent a common classification approach used in various ticketing systems. A Ticket may have one or more Tags associated with them.

Core resource which represents some work that needs to be carried out. Tickets are usually mapped to issues, tasks, work items, etc. depending on the underlying product.

Ticket Types represent the classification system used by the underlying products for Tickets. Some examples are bugs, feature, incident, etc.

Fields represent the attributes defined for various entities in the underlying product. Depending on the underlying product, custom attributes can be defined by a User on various entities like Ticket, Contact, etc. is_user_defined attribute within Field can be used to differentiate between custom and system defined Fields.

Ticket Status represents the completion level of the Ticket. Some products provide customizing the Ticket Status.

Users represent the people using the underlying ticketing system. They are usually called agents, team members, admins, etc.