Fact table
A fact table represents a primary table in a dimensional model. Fact tables describe a main object of consideration (fact), for example, an activity table.
Fact tables contain two types of columns: those that hold facts on the described object and those that serve as a foreign key to dimension tables.
Dimension tables contain the descriptions of the objects in a fact table, for example, enhancement tables. Fact tables aid in the description of dimensions, such as dimension values, characteristics, and keys.
Accordingly, in the relationship between fact tables and dimension tables, cardinality N is expected for fact tables and cardinality 1 is expected for dimension tables.
If several tables with an N:1 relation are concatenated to a star schema, the initial table in the center of the star schema represents the main object of interest (fact).
A fact table multiplies the data per case. This means that several entities are assigned to one case, for example, one case has several activities.