Database systemsPostgreSQL, MySQL, Visual dBASE, MS Access, MS SQL Server, Oracle ...
A database system would normally include functions to create tables, add data to the tables, extract data from the tables and display the extracted data either on screen or on paper.
In a relational database the data storage (tables) are separated from the data display (forms). Further, the two can be linked together by queries allowing you to extract and combine data from multiple tables. This separation gives many benefits, making the whole system more flexible and maintainable. This is the most common database structure today.
Client/Server databases are designed to be run over LANs, WANs or the Internet. Necessary for browser based access or many simultaneous users.