When my cow's milk sits for about a day, the very top of the cream is so thick I have to use a spatula (or my finger - LICK! YUM!!!) to get the cream off of the ladle. That is heavy cream. Then there is a layer between that really thick stuff and the milk - light cream which to me is comparable to half and half.
If I only use the heavy cream for making butter, I get tremendous yields and very little buttermilk. And, yes, you can use all of the cream for making ice cream.
Mascarpone is an excellent cheese to make with cream, then of course you have to make Tiramisu to use the Mascarpone. Diet out the window! But your tastebuds will know what heaven tastes like!