* article

   A case consists of multiple articles. An article goes through a channel.

* case

   All request are named case. In other systems this is also called issues, ticket, etc.

* channel
   Channels are the incoming and outgoing ways where articles flow. There are assigned to groups. Channels can be e-mail, chat, twitter, etc. New channels can be added via the plugin mechanism.

* group

   A group is a structure element like a container where cases are assigned to. A case can only be assigned to one group. 

* organization

   Organizations are used to group users. The common use case is to group the employees of a company to one organization.

* overview
   Overviews are configurable lists of cases. There are system wide overviews, defined by an administrator and user defined. They are available for all roles.

* role

   All permissions are role based. Access to groups are assigned to a role and also specific actions on requests depending on a users role.

* textmodule

   While writing an article are textmodules available to assist the agent's work.

* user

   Every persons which are used in Zammad are called person. Each person needs a minimum of one assigned role. Three roles are predefined: Administrator, Agent, Customer