I am a former database programmer and have only worked with binary (degree 2 relationships(relationships between 2 entities)) but here is a description of higher degree relationships that I found"
Degree of a Relationship
The degree of a relationship is the number of
entities
associated with the relationship. The n-ary relationship is the general
form for
degree n. Special cases are the binary, and ternary ,where the degree is
2, and
3, respectively.
Binary relationships, the association between two
entities
is the most common type in the real world. A recursive binary
relationship
occurs when an entity is related to itself. An example might be "some
employees
are married to other employees".
A ternary relationship involves three entities and
is used
when a binary relationship is inadequate. Many modeling approaches
recognize
only binary relationships. Ternary or n-ary relationships are decomposed
into
two or more binary relationships."
Degree of a Relationship
The degree of a relationship is the number of
entities
associated with the relationship. The n-ary relationship is the general
form for
degree n. Special cases are the binary, and ternary ,where the degree is
2, and
3, respectively.
Binary relationships, the association between two
entities
is the most common type in the real world. A recursive binary
relationship
occurs when an entity is related to itself. An example might be "some
employees
are married to other employees".
A ternary relationship involves three entities and
is used
when a binary relationship is inadequate. Many modeling approaches
recognize
only binary relationships. Ternary or n-ary relationships are decomposed
into
two or more binary relationships."