The term "write-update" refers to a specific type of database operation where data is both written to and updated in a database. This process ensures that the most current information is stored, allowing for accurate data retrieval and management. It is commonly used in applications that require real-time data processing, such as banking systems or e-commerce platforms. In a write-update operation, the system first checks if the data already exists. If it does, the existing data is updated with new information; if it does not, a new entry is created. This method helps maintain data integrity and consistency across various applications and systems.