What is the difference between alpha and beta glucose?

The difference between alpha and beta glucose is quite subtle.

Alpha glucose is what’s termed in chemistry a cis isomer while beta glucose is a trans isomer. Cis because the hydrogen (top, H) and hydroxyl (bottom OH) groups on the left and right of the glucose are on the same side of each other, and for beta glucose it’s trans because they are across from each other diagonally, and not on the same side.