Hi, I have recently been trying to understand the concept of distributed and centralized database architectures, with regards to a SQL Server 2008 R2 Database Engine. For example, a single database engine with a single instance but multiple databases or a single database engine with multiple instances and each instance having multiple databases. I'm confused as to which setup falls under which structure: centralized or distributed? Secondly, how does the user base get distributed under both these configurations? Lastly, how does it affect database performance (Figures of maximum database users and queries SQL Server 2008 R2 onwards can handle, would be nice)?