Single glazed glass is one layer of glass or can be known as single pane of glass. Single glazed glass is also available in improved forms, e.g. toughened glass etc.
A Single Glazed Window will provide you with maximum Solar Heat Gain Coefficient or natural sun energy; however with equally high U Value or insulation value, this heat or any natural heat is not likely to be retained inside the room and hence the impact could be minimum on comfort levels or energy efficiency, especially in comparison to double glazing.
A single glazed window is constructed using a single pane of glass. This means that the only thing separating your home from the outside environment, is that pane of glass. Typical window glass ranges from 3mm to 10mm.