What’s a Relationship in Access? Relationship in a database is the link between tables. You can link one table with another table or several tables through common data present in key fields and create a useful relational database. Forms, queries and reports assemble data through the help of relationships and give you the information you want in a single place. This data is easy to understand and use and you can update it, delete it, print it and do any other actions on it. Primary keys act as easy identifiers to common data for forming relationship. A primary key of a table repeated in a different table becomes a foreign key of that table.