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."