Audi stands for August Horch.
Audi is basically the Latin translation of the surname of August Horch.
August Horch was the founder of the Audi automobile company.
Horch is a German word which means Listen.
August Horch founded the Horch Motorwagenwerke Ag in 1899.
And in 1909, August Horch left the company and then founded thew new company known as August Horch Automobilwerke GmbH.
Horch was also unable to use his surname as the brand name because it was already trademarked.
And so a business partner suggested that Horch use the Latin Translation of Horch's name which is Audi.
The first Audi was also produced in the year 1910 and in 1932 Audi had merged with Horch, DKW and also Wanderer to form the Auto Union.
And in 1964, Audi then became a subsidiary of the Volkswagen Group.
The 4 rings in the Audi log represent the merger of the 4 previous companies that were independent that merged to form the Auto Union.