A database can be defined as a collection of data that is shared throughout the enterprise and used for multiple purposes. A datastore is a place for storing data. The difference between database and datastore is the keyword ‘shared’.
A DBMS is a computer system included with administrative tools used to manage the database. More precisely, a DBMS is a computer tool used to store data and provide a mechanism for manipulating and controlling this data. Some examples of DBMS are Ingres, Informix, Oracle or Sybase. A DBMS is illustrated below.
The screen above shows the physical data in computer file system. Normally, PDM users just retrieve, edit, and update the product data without worrying what actually happens in the underlying computer file system.