Frontpage is a post Home tab is a page. why are they different?

I seem to have noobed it up good and proper here. When you go to my main site. the info there is the welcome to wordpress post. However the HOME tab is of course the page that I built. How do I get the home page to act as the front page. I am surely not the first one to have this problem but I could not find anything in the faqs and how to’s…I appreciate your help, and I thank you in advance.