Migrating from DTD to XSD and for some reason the transition is a bumpy one. I understand how to define the schema once I'm inside the <xs:schema> root tag, but getting past the header & namespace declaration stuff is proving to be especially confusing for me.

I have been trying to follow the well-laid out tutorial on W3S but even that tutorial seems to assume a lot of knowledge up front.

I guess what I'm looking for is a King's English explanation of which attributes do what, where they go, and why:

• xmlns
• xmlns:xs
• xmlns:xsi
• targetNamespace
• xsi:schemaLocation

And in some cases I see different variations of these elements/attributes, such as xsi which seems to have two different notations like xsi:schemaLocation="..." and xs:import schemaLocation="...".

I guess between all these slight variations I can't seem to make heads or tails of what each of these does. Thanks in advance for bringing any clarity to this confusion!