Glycosidic linkages between monosaccharides can be which configurations?

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Glycosidic linkages can be alpha or beta because the bond forms at the anomeric carbon of one sugar, and the orientation of the substituent attached through the glycosidic oxygen defines the configuration. If that substituent points downward (below the ring plane in Haworth notation), it’s an alpha linkage; if it points upward (above the ring plane), it’s a beta linkage. This stereochemical arrangement at the anomeric carbon is what distinguishes different disaccharides and polysaccharides, such as alpha-1,4 versus beta-1,4 linkages. The other descriptions don’t capture this stereochemical orientation at the anomeric carbon.