Orange juice is the liquid expressed from the orange citrus fruit. Most of the juice oranges in the U.S. are grown in Florida as opposed to the eating oranges grown in California.
Orange is available in a myriad of options from no pulp, to high pulp, low pulp, filtered and so on. While oranges are certainly a wonderful food, the juice has its downsides. Oranges have a very high sugar content and are high on the glycemic index scale (50). If you do drink orange juice make your own or go for the high pulp variety.