CVS tries very hard to be a competitor of Walgreen's and for the most part they succeed.. Greater Phoenix is one of those markets where CVS and Walgreen's compete head to head.
My impression is that they are a retailer that offers goods and products at a slightly lower price to Walgreen's. The reason I'm hesitating is that the staff seems overworked sometimes. I like the store, but I know I would not want to work there.