Planes was the title of the 2013 Disney spin-off set in the world of Pixar's Cars.
Planes centers on Dusty Crophopper, a crop-dusting aircraft who dreams of competing in an international aerial race. The film uses the vehicle-centered premise associated with Cars but shifts the action from roads and racetracks to the sky.
Disneytoon Studios produced Planes, and Walt Disney Pictures released it in 2013. Although it is connected to the Cars setting and includes references familiar to that world, Pixar did not produce the film. That distinction is important because the visual style and franchise branding can make it seem like a Pixar feature.
A sequel, Planes: Fire & Rescue, followed in 2014. Planes is therefore a Cars-related spin-off, not the title of a fourth Pixar Cars feature or another name for Cars 2.