The friendly cow all brown and white
I love with all my heart:
She gives me cream with all her might
To eat with apple tart.

Not great poetry (would you believe it's by Robert Louis Stevenson?) but a great sentiment. And there are so many different kinds, with different uses.

Cream is graded by the amount of butterfat it contains. That's the globules in milk that rise to form a layer at the top of whole milk and are skimmed off to present as cream or churned to make butter. 

Heavy cream or heavy whipping cream must contain 35 percent butterfat or more. This is less than the double cream common in Europe which must contain not less than 48 percent butterfat and which consequently produces a much denser, richer cream when whipped.

Whipping cream must contain not less than 30 percent butter fat, making it whip to a lighter consistency than heavy cream.

Table cream must contain not less than 18 percent butter fat. It won't whip up but can be used in cooking or for pouring over desserts like pies and fruit salads. Single cream is the British equivalent.

Half-and-half cream must contain no less than 12 percent cream. Half milk and half cream, it's popular for pouring into coffee and for using to finish soup and sauce recipes where cooks don't want the fattier creams. 

Sour cream is table cream containing not less than 18 percent fat to which lactic acid has been introduced. 

Clotted cream should only be eaten in England where it comes from. What you can buy as clotted cream in jars in the U.S. bares no relation to the real McKoy. That's a cream which comes from the West Country, the counties of Cornwall and Devon, and is commonly served with warm scones and strawberry or raspberry jam. It's butterfat content is at least 55 percent. To produce it, whole milk is scalded then cooled overnight. In the morning an almost yellow crust of cream is skimmed off the top. An approximation of it can be achieved by mashing 3 ounces of plain cream cheese then adding 1 tablespoon of sugar. Once that's incorporated, slowly beat in 1 cup of whipping cream little by little to loosen it, then beat it with an electric mixer until it's almost unmoveable.

Creme fraiche in France is made from unpasteurized cream so its natural 'good' bacteria ferment it naturally to produce its tangy taste. That's not allowed in the U.S. So sour cream is added to encourage fermentation. Make it by shaking a cup of whipping cream with 1/2 cup of sour cream, both at room temperature, in a clean lidded jar for about 20 single jerks. Leave it out for 24 hours, giving it a single jerk a couple of times, then store it in the refrigerator for a day before using.