A window profile is a window frame or, in other words, a window bearing element installed along the perimeter of a window opening. A double-glazed window and window fittings are installed in the window profile.

Window profiles are made of wood, aluminum, steel and fiberglass, but in this article we will talk about window profiles made of PVC (polyvinyl chloride).

In the USSR, plastic windows were developed in the late 50s, but it did not go beyond prototypes and glazing of several multi-storey buildings. In the West, the mass production of plastic windows began in the early 60s. Due to the ease of production and high performance, plastic windows have become widespread.