Activity objects showcases various object types in the Journey specifications. It contains a unique jouney id, type of activity, a list of outcome and arguments object
Event which gets triggered as per user action like click event which represents when a user clicked on a link in the message
Journey or an interaction is the root object to create Jorney Specification which contains list of triggers, goals,activities, and defaults which have a list of email expresssionsto identify which email address to use as a default
A link which is there in the message, while this object does not support methods but some properties can be returned through the LinkSend object and retrieve method.
A subscriber is a person who subscribes for a communication in the form of email or sms, the subscriber object is the instance of this person.