The basic sauce you need to know:

Espagnole (brown sauce): This is made of dark roux of cooked flour and butter as well as brown stock made from roasted bones and vegetables.

Béchamel: a basic white sauce that is made from milk, butter and flour. Sometimes cheese is added.

Vinaigrette: This is simple oil and vinegar sauce. Sometimes other ingredients are added, such as garlic, shallots and herbs.

Hollandaise: a mixture of egg, oil or butter, and mayonnaise.