SSAS: Dimension Relationships in Cubes

“Dimension relationship” refers to the direct or indirect relationships between dimension and its measure groups in a Cube.

Regular Refers to a standard relationship, when a Key column in the dimension is directly joined to fact table.
Reference When a Key column in the dimension is indirectly joined to fact table by referencing another dimension.
Fact / Degenerate Dimensions constructed from attribute columns in fact tables than from attribute columns in dimension tables.
Many-to-Many One dimension is associated with multiple facts

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