David said:
Aloe gel is the undiluted gel taken from Aloe leaves, the juice is a diluted product (usually with water and often a sweetener). For medicinal purposes I would not use Aloe juice. The whole leaf juice contain Aloin, which is a purgative and potentially toxic. If the product is clear then it is has been decolorized, which I suspect removes most if not all of the Aloin, but I would use the clear leaf gel only, and clinically I find the gel from a fresh leaf much more effective than the bottled products which often contain stabilizers.