Relationship in Salesforce is a 2-way association between 2 objects. Using relationships we can link objects with each other and we can make connections and display data about other related objects.

In relational database

To create a relationship between two tables we use the concept of Primary Key and Foreign Key.

Primary Key:

It resides on the table which is one in a many to one relationship.

Foreign Key:

It resides on the table which is many in a many to one relationship.

In Salesforce to create relationships between two objects, we use relationship fields. The field is created on the many side object and it is related to the one side object.

In salesforce there are basically 2 types of relationship fields:

• Master-Detail Relationship
• Lookup Relationship