The Flash is one of Superman's colleagues in the Justice League.
The Flash's main power is Super-Speed. He normally runs around 90-150 miles per hour. This is fast enough to move through most cities and around people without causing too much disruption to the population and slow enough for him to register everything he sees clearly. If he chooses, Barry can approach the speed of light, and doing so, enters the Speed Force dimension.
Jay Garrick, Bart Allen, Wally West, and most notably Barry Allen have all been known as the Flash. They have at one time or other raced Superman. Although the results of these races vary, most times the Flash beats Superman.