Cream is made from the butterfat layer that rises to the top of milk that has not been homogenized.
Different types of cream arise from the fat content of the cream, and whether or not the cream has been "soured" by adding lactic acid bacteria to give it a tangy flavor. Heavy cream contains around 35-45% butterfat and light cream around 18-30%; both are not soured. Half-and-half is a mixture of cream and whole milk with between 10.5-18% butterfat. Crème fraîche is a type of sour cream with about 30-35% butterfat. Sour cream is, as the name suggests, soured, but it is generally lower in fat—between 10-20% butterfat.
Be careful with lower fat creams, when mixed with alcohol or another acidic ingredient or when subjected to high heat, they are more likely to curdle than higher fat creams.1
The nutrition DNA of cream. For example, you can see that 100g cream covers 144% of your daily need of Saturated Fat and 57% of the recommended Fat intake. Hover over the bars to see which nutrient is covered.