Harley-Davidson, or H-D for short, is an American motorcycle maker that started making motorcycles near Milwaukee in 1903. The company makes heavyweight motorcycles that are designed for cruising on the highway; they're called Harleys. Harley-Davidson is one of two big U.S. companies that made motorcycles that was still in business after the Great Depression; the other closed down in 1953.
Harleys have a special look and sound. Most new Harleys, except the V-Rods, are made to look like old Harleys. Harley-Davidson made small motorcycles in the US and in Italy, but they didn't sell well enough. They stopped making small motorcycles in the US in 1966 and in Italy in 1978.
Harley-Davidson and their motorcycles have many fans. The fans can join clubs and go to events or to Harley-Davidson's museum. Apart from selling motorcycles, Harley-Davidson also charges fees for companies to put Harley-Davidson's logos on the things they make. Less than one-hundredth of the money Harley-Davidson made in 2010 came from these fees.