In a pair of anomers shown as Haworth formulas, the anomer in which the hydroxy group or the alkoxy group on the anomeric carbon is pointing down is called the alpha anomer, and the one in which is pointing up is called the beta anomer.

eg. 1:  anomers of D-glucopyranose

eg. 2:  anomers of D-fructofuranose

eg. 3:  anomers of methyl D-glucopyranoside