Database relations primarily consist of three types: one-to-one, many-to-many, and one-to-many. The one-to-many relationship is the most common, where one entity, like a customer, can be linked to multiple entities, such as orders. In a one-to-many setup, each order is associated with only one customer, while a customer can have many associated orders. To establish this connection between tables, the customer table includes a primary key, such as customer ID, while the order table has its own primary key, like order ID. To link these, the order table adds a foreign key column that references the customer ID. This avoids data redundancy and maintains normalization in the database. Foreign keys can be repeated as they reference primary keys from another table, allowing for efficient linkage. For instance, if a customer with ID 201 has placed three orders, the order table will display these orders and can be queried to retrieve customer details, confirming that the relationship maintains the one-to-many structure. This design prevents violations of normalization rules, ensuring data integrity and performance in database operations.