SQL stands for  Structured Query Language, the language used for created, retrieving and modifying data in most modern databases.

RoSE uses MySQL for the database system since it is free, open source and proven for large scale installations.

SQLite is a novel lightweight database system that operates as a small programming library that is embedded into the program that needs to use it to store configuration information (such as Photoshop, Skype or Firefox) but does not deal with the large volumes of data that standalone database systems are designed to handle.

SQLite would be a good way to learn about databases through the use of standalone database explorer programs. One such explorer program is the SQLite Database Browser, available at http://sqlitebrowser.sourceforge.net/