Refers to changing one or more of a product's characteristics; while, a is the development of a product closely related to one or more products in the existing product line but designed specifically to meet somewhat different customer needs.

Driving would be more pleasant if we didn't have to put up with the bad habits of other drivers. a newspaper reported the results of a valvoline oil company survey of 500 drivers in which the drivers marked their complaints about other drivers. the top complaints turned out to be tailgating, marked by 24% of the respondents; not using turn signals, marked by 19%; being cut off, marked by 15%; other drivers driving too slowly, marked by 12%; and other drivers being inconsiderate marked by 5%.