Relationship means how two (or more) tables are connected with each other.
There are three type of relationships
1) One to one
2) One to many
3) Many to many
Say we have table1 and table2
For one to one relationship, a record(row) in table1 will have at most one matching record or row in table2
For one to many, a record in table1 can have more than one record in table2 but not vice versa if record from table2 is also connected to more then one record of table1 then it is called many to many.
The degree of a relation is the number of attributes n of its relational schema. An example of a relational schema for a relation of degree seven, which describes university students, is the following:
STUDENTS(Name, Ssn, Home_phone, Address, Office_phone, Age, Gpa)
