Café crema was the original name for espresso because of the crema it produced. Café crème is the French translation. Espresso became the more popular word.

Now it's when you make a long black / americano style drink but instead of adding water before / after pulling the shot, you run the full amount of water through a coarser grind when making the espresso.

Americano = water after shot
Long black = water before shot
Café crema = water through shot

Little anecdote: I've been to Paris a fair bit, and always enjoy a big bowl of cafe au lait with my morning pastry. First time in Nice, the waiter mocked me for my order. "Café olé!" he shouted and did a little flamenco dance. In the south of France, he explained, they call milky coffee "café crème". So there you go.

In the UK an Americano is just a watered-down espresso, no milk or cream.