Dytecture Double glass pane windows has 2 layers of glass, usually with an argon gas in between the glasses for added insulation value. Not sure what is meant by 'normal' glass pane.
Main Line Kitchen Design Double paned windows called insulated glass eliminate the need for storm windows. Double Hung type windows where the sashes go up and down will usually tilt in for easy cleaning from inside. "Low E" glass is where there is an inert non conducting glass like Argon between the two panes making the glass even more energy efficient. Most low e glass also has coatings applied to the glass itself to reflect heat. There are concerns about low e glass and the focal points of reflected light that can created by the glass. The panes can act like a magnifying glass and melt a neighbor's siding or create other problems with their focused light reflections.
Interiors Unleashed Yes! and conserve heat in cold country. Historically this heat/cool exchange at windows was helped with drapery. Insulating curtains and blinds can make a big difference today as well. Closing curtains and/or blinds at night in cold areas will make a big difference. Doing the same during the heat of the day in a warm country will make a surprising difference regardless of double or single panes.
We could all save a little energy and money on heat and cooling.
Kevin Retired Decorator Double pane glass is always better in all weathers. But in hot climates also check out UV glass to reflect the sun if your shopping for windows. Check the R factor for a window the higher the R factor # the better it is to insulate. ie R17 R24 etc Go to a window expert to gather info. then shop the price where they might not have the knowledge but you will.
We could all save a little energy and money on heat and cooling.