Crème fraîche is particularly useful in finishing sauces in French cooking because it does not curdle. However, “light” crème fraîche with a low fat content curdles when heated.
Crème fraîche is a substitute for sour cream.
Clabber is a similar food made in the Southern United States.
Crema Mexicana is a cultured sour cream, often sold in supermarket dairy aisles in regions where crème fraîche is unavailable.