Associations are the general form for the representation of relationships between topics in a topic map. An association can be thought of as an aggregator of topics. That is, an association is a grouping of topics with no implied direction or order, and there is no restriction on the number of topics that can be grouped together.
An association can be assigned a type (again defined by a topic) that specifies the nature of the relationship represented by the association. In addition, each topic that participates in the association plays a typed role that specifies the way in which the topic participates. For example to describe the relationship between a person, "John Smith," and the company he works for, "ABC Limited," we would create an association typed by the topic "Employment" and with role types "Employee" (for the role played by "John Smith") and "Employer" (for the role played by "ABC Limited").
The structure of an Association
Like names and occurrences, an association can be assigned a scope in which it is valid, and which may be used by a topic map-aware application to determine whether or not to display the information represented by the association to a user in a given situation.