The 419 scam is so called because it refers to the
"Nigerian Criminal Code" that prohibits cheating and dealing with
fraud in Nigeria and other countries in Africa that promises a large amount of
money such as a lottery prize, inheritance, money sitting from a bank account
etc.
Most people receive emails from people claiming to be
bankers and how they have money to give to you. They claim to know you however
they really don't know you at all.