What is the purpose of a window sash stop and how does it contribute to the security and functionality of a window?

A window sash stop is a device that limits the opening of a window sash to a specific position. It contributes to the security of a window by preventing it from being opened too wide, which can deter intruders from entering a building. Additionally, it enhances the functionality of a window by allowing for controlled ventilation while maintaining safety and privacy.