What did henry ford introduce in order to make vehicles more affordable?

The assembly line which produced a more affordable car.

In 1913, Ford introduced the first moving assembly line for the production of an automobile, which reduced the time needed to build a car from twelve hours to two and a half hours.

The Model T, meant as an affordable car, had been introduced in 1908 at a cost of $850.  With the use of assembly-line production, by 1925 Ford was able to reduce the purchase price of a Model T to under $300.