Cruise control. How does it work.

[Holophyte]

Went out today and had to use the M62. There is a section in here where you go up a hill until you reach the highest summit of any motorway.

I had the cruise control on set at 70mph. It stayed at 70mph all the way up and stayed at 70mph all the way down. So my question is. How does this work? Does it use more acceleration going up hill and does it use the brakes going down hill? Or does it use momentum and reduces the revs going down hill to keep a steady 70?

How ever it's done it's flippin good technology!!!