The key points to understand about relational and flat file databases are the following:

1. Relational databases differ from older, nonrelational databases because information is stored at random in the relational model, then organized as it is retrieved.
2. Older databases typically use more proprietary query approaches--often hard-coded applications, as compared with dynamic queries, submitted by both the user and applications.
3. SQL relies on the foundation of a relational database. The engine you are working with must support the SQL characteristics to querying. Compatibility with SQL is not an assumed capability of older database engines.

If you are interested, here is some additional information about other approaches to databases.
In the next lesson, we'll use an analogy to drive the relational database point home.

Take a brief quiz to make sure to understand these flat file and relational database concepts.
Database Flat File - Quiz