Hey Michael - thanks for your comment and for watching the video!

Namespaces in InterSystems IRIS or Health Connect are logical layers of abstraction that refer to one or more databases. They help organize and manage data and code logically. While databases are physical files storing data and code, namespaces act as references to one or more databases, offering flexibility in managing and accessing data and code.

Using namespaces to simulate environments, like test harnesses, provides an integrated approach within the IRIS environment. Here's a video that walks through an example use case that a Health Connect implementer might leverage -- using multiple namespaces to simulate the systems they are setting up for a customer.

Separating code and data within namespaces is typically a good idea for security & scalability. Your installation manifest example appears to keep code and data in the same database (named after the namespace), which can also be OK; but it would be a common practice to choose different databases for code and data within that namespace. I'm probably not the best person to speak to true best practices on that front... However, I think this video might also be helpful for you in understanding the distinction between namespaces and databases.

Thanks again for your engagement!