If I remember right - there are SEVEN (7) Mother Sauces.
Marie Antoine (Antonin) Carême codified 4:
Allemande, based on white stock, thickened with
egg yolk
Béchamel, based on milk, thickened with roux
Espagnole, based on brown stock, thickened with roux
Velouté, based on a white stock, thickened with roux
Carême's number 1 student/disciple
Georges Auguste Escoffier added 3 more to the list of Mother Sauces based on:
tomato based sauces (take your pick)
butter based sauces - like
Hollandaise
emulsion based sauces - like
Mayonnaise
Like College_Cook said - if you want a basic foundation in classic French sauces - get Escoffier's book
Le Guide Culinaire - or if you want it in English, and for a few bucks less,
try this one, or wade through the
e-Bay listings ... or check your local library.