In DNA, Glycosidic Bond, N-C linkage connects Sugar with Nitrogenous base.
The C1 of deoxyribose forms β-N-Glycosidic bond with nitrogen-9‘ of purine (Adenine and Guanine) bases or with nitrogen-1 of pyrimidine (Thymine and Cytosine or Uracil in RNA) bases
It is called beta as the OH in first C deoxyribose is above the plane.
This 2 minute video will explain How glycosidic bond is formed in DNA?
As water is removed during the reaction, the reaction is called dehydration condensation reaction.