Can someone tell me what a “VINTAGE 2 SERIES” Chanel bag is?

That probably refers to the serial number--it is a vintage bag and the serial number starts with a 2...right now the serial numbers start with an 11--or has it moved to a 12? Losing track...
 
Let's correct some misstatements. The series 2 bag is an early Chanel and does not feature a holographic tag. The series is indicated by the first number(s) in the authentication string. The holographic tags began at series 5 or 6 and after Karl Lagerfeld came on board in 1983. So, if series 5 was being manufactured in 1983-84 and you have a series two and each series runs about two years.,..you have a very fine vintage bag circa 1975. Early bags carry 7 digits on the interior tag. Newer bags carry 8 digits...makes sense since Chanel is now producing series 12....hence the extra digit.