In cold climates, condensation collects on windows when the temperature of the glass drops below the dew point of the inside air.
Minor sweating is normal with most windows, but excessive condensation can contribute to the growth of mold or mildew in or on the walls. Newer low-e, double-glazed windows can reduce frost and condensation because interior glass surface temperatures are warmer. In an existing home with older windows, the simplest and most effective way to control condensation is by reducing interior humidity. Using vent fans (in the kitchen and bathrooms) and dehumidifiers also helps lower interior humidity levels. When purchasing windows new a lower U-value generally indicates greater condensation resistance.
Article This Old House 2013 by Joe Hurst-Wajszczuk
There are quite a few ways to eliminate this and a great long term way is to buy storm windows since there a two windows the space between the two windows allows the interior window to stay warmer. A simple approach would be to raise the temperature inside the home or turn your ceiling fans on to move warmer air down.
Another way to eliminate this easily but more expensive is to buy a dehumidifier or multiple mini dehumidifiers. A cheaper short term alternative is purchasing moisture eliminators like damprid to use in the windows.