A database is a collection of data that is stored together in a certain way, can be shared with multiple users, has as little redundancy as possible, and is independent of application programs. It can be regarded as an electronic filing cabinet-a place where electronic files are stored. Users can add, query, update, delete and other operations on the data in the files.  It has a large storage space and can store millions, tens and hundreds of millions of data.  However, the database does not store the data at will. There are certain rules, otherwise the query efficiency will be very low.  In addition to text type data, images, music and sound are all data.