Database theory is a branch of computer science that focuses on the design, implementation, and management of databases. It provides the foundational principles for organizing and storing data efficiently, ensuring that it can be easily accessed and manipulated. Key concepts include data models, which define how data is structured, and query languages, such as SQL, which allow users to retrieve and manipulate data. Another important aspect of database theory is the study of database normalization, a process that reduces data redundancy and improves data integrity. This involves organizing data into tables and establishing relationships between them. Overall, database theory is essential for creating robust systems that handle large volumes of data effectively.