Taxonomy Tables With Sample Data

I’m trying to understand the WordPress structure before actually implementing a WP blog. None of the online docs/articles I read clarify how the terms, taxonomy, and relationships tables work. So, e.g., term_group groups terms, but how does it actually function on a web page or in relation to other tables? In wp_term_taxonomy, if term_taxonomy_id uniquely identifies a term-taxonomy pair, is it not a unique key? So, what does term_id_taxonomy do? I have been looking for an example of these three tables illustrated with sample data that might clarify how they actually function, but I haven’t found an examples. If anyone could point me in that direction, I would much appreciate it.

WP Newbie (That’s my actual name….Or not)