Blurred action- Blurred action is when a picture is taken with a low shutter speed and more exposure time. Which makes an object or objects seem like they're still in motion. Like in the picture to the right.
The background and objects without movement are shown as a still image. While the cars and people are blurred, showing their motion. So the picture shows not only one instant in time, but a few.
Stopped action- Stopped action is when a picture is taken with a faster shutter speed and less exposure time. This makes the object, moving or not, be still like in the picture to the left.
When the picture was taken, the model was still moving. However, with the faster shutter speed the photographer was able to capture her in one instant. Even the purple object on the wall behind her, which could have been moving at the time the picture was taken is still.

The picture to the right is a comparison of blurred action and stopped motion. The soccer player in the top picture shows blurred motion, while the bottom shows stopped motion.
Panning-Panning is the horizontal movement of a camera. When used in photography it's used to show or suggest fast motion. The background will look blurry, but the main object will appear still. Like in the picture to the left. The car looks like it's moving pretty fast, which is suggested by the background being so blurry in the opposite direction that the car would be moving in. However, the car itself doesn't show motion.