Glazing refers to the installation of glass in windows, doors, or any other fixed opening in the world of construction. It can also refer to the work done by a professional "glazier"). Glazing can be mounted on the surface of a window sash or door stile, usually made of wood, aluminum, or PVC). The glass is fixed into a rabbet (rebate) in the frame in a number of ways including triangular glazing points, putty, etc. ). Glazing can be single, double, or triple glazed, and the term can refer to the glass itself, the window glazing compound, which is a putty that holds the window glass in place, or the installation of the window glazing compound.

Common types of glazing that are used in architectural applications include clear and tinted float glass, tempered glass, and laminated glass as well as a variety of coated glasses, all of which can be glazed singly or as double, or even triple, glazing units). Single-pane windows are windows with a single layer of glass, while double-pane windows have two sheets of glass with a space in the middle, and triple-pane windows have three sheets of glass with two spaces in between.

Glazing is important in increasing energy efficiency in the home, and selecting the right type of window glazing for your home and area can save you a significant amount of money in energy costs.