1.what is database?
A database is a structured collection of records or data that is stored in a computer system. The structure is achieved by organizing the data according to a database model. The model in most common use today is the relational model. Other models such as the hierarchical model and the
network model use a more explicit representation of relationships.

2.what is database system?
database system is a term that is typically used to encapsulate the constructs of a data model, database Management system (DBMS) and database^[1].

3.write examples of database system and their databases.