Questions about TAGS

I’m trying to understand how to use Anspress tags. It seems that if you have no TAGS (extension) you have NO related Questions and also NO Breadcrumbs (why no breadcrumbs?).

But i fail to understand how the tags work. It seems that you must PREDEFINE all the tags you need and that each user can’t add his tags while asking. Not sure if this is normal or not.

Can somebody give me some more hints about all that ?

Thanks