Application Development Software

For my project we must use WebCenter to develop and application for a client. I just have a few questions on how they all work together.

From what research I have done, Sites and Portal do roughly the same thing. Just Portal gives you more control and Sites is easier to use for non-technical users. Also there is nice caching abilities within Sites. So why would I want to integrate them together?

Now how would I integrate them together? I know it is possible because I read [This Blog|https://blogs.oracle.com/ATEAM_WEBCENTER/entry/integrating_webcenter_sites_with_webcenter] . I don't feel that gives me enough meat. Are there any tutorials on integrating them together or more technical documentation I can read?

So I guess my main overall question is why would I want to use them both together, when I feel Portal can do everything Sites can do(and probably more) without the non-technical user support.

Thanks in advance,
Dustin