Lookup relationship is a child to parent relationship that allows us to relate one object to the another object. The object on which the relationship is created considered as child object, and the object at which the relationship points is considered as parent object.
Salesforce provides various standard fields for each Salesforce objects. In every business, they use common standard fields like firstname, lastname, company name, date, amount, status, account, etc. But sometimes standard fields aren’t enough to cover the all the important information of the record. To fulfill this requirement, we use custom fields.
