Teach me wordpress – For Contractors Only

So many ask us this question, what are all of these different parts of wordpress?  I must admit even we can get confused.  The focus is on differentiating the difference between the following;  Wordpress post, wordpress categories, wordpress tags, wordpress services, wordpress pages, wordpress slugs, wordpress permalinks.  Sounds like credits rolling at the end of a movie and most people do not know the differences or how they affect your website.