Types of Computer Databasesby J.T. Barett
Database Management Systems (DBMS) free the programmer from dealing with the low-level details of storing records. When she wants a record, she codes a few simple commands in her program, and the DBMS takes it from there. From simple beginnings, database software has grown in sophistication, taking many forms, from inexpensive standalone PC programs to multinational networks costing millions of dollars.
Introduced in the 1960s, these were the first databases. They maintained records and pointers between them but had no indexing or search.
These databases allow one to many relationships, as with an order and its line items. A record can be looked up using an index, speeding up searches.
In a relational database, data are organized into tables. Different tables can be connected by common data fields, allowing complex, ad-hoc relationships and sophisticated data retrieval.
A server-based database performs all data access in a separate process outside the application program, usually on a separate computer. The server program enforces data integrity rules, resulting in a more reliable database.
Some databases are complete application environments, including data management, programming languages and data entry forms.