Arm and Hammer is known for baking soda primarily, and so of course their toothpaste is manufactured with....baking soda! Go figure. There are many versions of Arm and Hammer's line of toothpastes, but this is the Advanced White version, which also contains peroxide. It is supposed to whiten your teeth with repeated use.
I am not sure about the whole whitening thing- I personally have not noticed any difference, and I have been using this toothpaste for about 4 weeks now. As a toothpaste, though, I would absolutely recommend it to anyone- the texture has a little bit of grittiness to it (that's the baking soda)- this really helps to make your teeth feel extra clean when you are done brushing.
The flavor is nice too- not so overpowering that your mouth burns after using it, but it makes your mouth feel fresh. So if you are looking for something to whiten your teeth, I would maybe suggest looking elsewhere. But if you are looking for a great tasting toothpaste that gets your teeth clean, check this one out!