Difference among MS, MS-PHD, and PHD

<p>I had a quick question regarding MS, MS-PHD, and PHD.</p>

<p>Entering a PHD program is far more vigorous than an MS program... However, is an MS-PHD program also much harder to get in than an MS program? </p>

<p>My other question is, what is an MS-PHD program? If I get accepted, does this mean that I am also accepted to the PHD program? Or does this program imply that I am accepted to the MS program, but need to re-apply to the PHD program.</p>

<p>Thank you in advance!</p>