Third Normal Form (3NF) is a database normalization technique used to reduce data redundancy and improve data integrity. A table is in 3NF if it is already in Second Normal Form (2NF) and all its non-key attributes are not only dependent on the primary key but also independent of each other. This means that no non-key attribute should depend on another non-key attribute. Achieving 3NF helps ensure that each piece of information is stored only once, making updates easier and reducing the risk of inconsistencies. By organizing data in this way, databases become more efficient and easier to maintain, ultimately leading to better performance and reliability.