The so-called "database" is a set of data that is stored together in a certain way, can be shared by multiple users, is as redundant as possible, and is independent of applications. In the database, users can add, query, update and delete data in files.
Because using io stream files to store data has many disadvantages, such as low storage efficiency and troublesome storage and retrieval operations, generally only a small amount of string data can be saved. In order to solve these disadvantages, with the database, using the database to store data can solve these disadvantages well.
Database management system:
Database management system is a computer software system designed for database management, which generally has basic functions such as storage, interception, security and backup.
Database management systems can be classified according to the database models they support, such as relational and XML. . Or classified according to supported computer types, such as server clusters and mobile phones.
Or classified according to the query language used, such as SQL and XQuery；; Or according to the focus of performance impulse, such as maximum scale and maximum running speed; Or other classification methods.