Generation means which model (NOT LX, DX, EX) or revision of the accord it is... Not sure when the original accord came out (GEN 1) probably in the late 1980's... The new ones are now 7th Generation. A 2002 Accord was 6th Generation.. 2003-2005 are 7th Gen.... Basically, it refers more to body styling than anything else....

Hope this helped!