Experienced vB hackers -- Question!

[bigmattyh]

I've got a question for the guys who've really delved into the vB code. I've been programming my own stuff in php for some time now, and I'm currently working on a way of making the rest of my site integrate more or less fully with the existing vB.

So, I'm trying to make sure I understand the fundamental structure of how vB works with templates. I think it works like this, and please correct me if I'm wrong:

1) vB decides which templates it needs, based on which individual file is called and what action is taken. Some of these are preset (based on the action taken), some are dynamically decided upon based on individual factors involving the user.

2) vB gets the templates out of the database and passes them to the cache in sequence (? -- this I'm iffy on...)

3) vB goes through the templates, and replaces the variables in the curly braces with the appropriate replacement set

4) vB spits out the final string

Is this right, in general? Am I missing any major steps? I'm seriously interested in developing a custom-made portal-type interface with vB, and any help on this matter would be greatly appreciated. Thanks!