1. The database (database, DB) in accordance with the data structure to organize, store and manage a data warehouse, is a collection of some of the data stored in an organized manner.
2. The database contains relational databases, object-oriented database, as well as a variety of emerging XML database, the most widely used is the relational database.
3. Common database data model is mainly hierarchical model, network model and relational model
4. Relationship Model: a two-dimensional table data is described (table). In the relational model, each table has a plurality of rows and columns of fields, each field has a fixed column attributes (numbers, characters, date, etc.). Simple relational model data structure and clear, with high data independence, so is the mainstream database data model.