Google Hosted Services vs. Google Hosted


Okay, here is a question I have been wondering about for a while. What is the difference between Google Hosted Services and Google Hosted? Whenever I create a domain or edit one, I have the choice to use Google Hosted Services which there is a checkbox to “use gmail for your email at this domain”, as well as "setup and Underneath that is a seperate box that says "Google Hosted - “ONLY use Google to host this domain, including Google Apps, Gmail, and Google Sites”. So what is the difference between the two?