1. A Database is a computer term used to mean a file or files where data is stored in a central location for access by one or more users. A database differs from a document file in that a document generally is only accessible by one user at a time and is organized by pages. A database is generally capable of being accessed by many users at once, with each user being able to read and save information at the same time.
2. SQL stands for Structured Query Language which is a programming language used to query (ask for) information from a database.
3. R2 stands means Release 2 and is a designation Microsoft has used for its server products when it has made major changes to the product and it releases it as a new version. When R2 is not part of the name of the server product, Release 1 is implied.