The simplest way to say "Visual Studio 2005 Team Suite Edition for Database Professionals". A suite of tools built by Microsoft for designing, deploying and testing SQL Server databases within the Visual Studio IDE.
Very Large Database. Typically considered a database with a total size ranging from hundreds of gigabytes (GB) to terabytes (TB), contining millions or billions or rows. Designed with scalability in mind, they use different performance optimisation techniques to smaller sized databases.