Describe different types of relationships with examples:

There are three types of relationships:
a. One-to-one (1:1)
b. One-to-many (1:M)
c. Many-to-many ( M:M or M:N)

a. One-to-one (1:1) – One-to-one relationship exists between two entity sets
if an entity in the first entity set has only one matching entity in the second
entity set, and vice versa. For example, a manager and a department.
b. One-to-many (1:M) – One-to-many relationship exists between two entity
sets if an entity in the first entity set has only one matching entity in the
second entity set, but an entity in the second entity set has many matching
entities in the first entity set. For example, an employee and a department.
c. Many-to-many ( M:M or M:N) – Many-to-many relationship exists
between two entity sets if an entity in the first entity set has many
matching entities in the second entity set, and vice versa. For example, a
student and a course.