This is the most famous meteor shower of the year. The remainings of the comet Swift-Tutle, discovered in 1862, produce more than 60 meteors per hour.
The dust that enters the upper layers of the Earth atmosphere with velocities of 210 thousand kilometers per hour bocome incandescent and produce the trace we call falling star or meteor.
The comet Swift-Tuttle has a period of 133 years and a very excentric orbit that goes beyond Pluto. Its last visit to the inner solar system was in 1992.