Old fashioned windows that slide up and down are called what?

A traditional sash window comes with two sliding sections, also called sashes. They slide up and down, using a pulley and weight mechanism inside the window frame. When a sash opens, the weight counterbalances with a weight inside the window frame. This weight connects to the opened sash through a cord that runs over a pulley at the top of the window frame. This method is a simple cord, weight, and pulley mechanism. Generally, sash windows are designed in a manner that you don’t see the intricate functional mechanisms.

Source: Gowercroft Joinery