Escargot (snail) or Oyster?

My girlfriend and I were watching a show on television where chef gordan ramsy was holding a french cuisine (live version). He was holding snails. My girlfriend swears they are called oysters...i know...but I politely said they are called snails and are served in France as the term "Escargot". She still swears the french call them oysters and they are served in a spiral shell. I showed her a picture of a snail so we can both agree we are talking about the same thing. I again told her that oysters are a member of the mullusk family and are also a food but not the same....(not that I need it but I would love some back up, please) Who is right?