The tempered glass is a hardened glass specifically designed to cover and protect your mobile screen from scratches and other damages. It does not affect the functionality of the screen. In case of a drop, it does not guarantee that the screen won't break along with it, but it provides additional protection.
It features adhesive across its entire surface, unlike edge glue glass protectors which have adhesive only around the perimeter. This ensures easier application and smooth operation of the touch screen. Additionally, it prevents dust from passing underneath, which can happen with edge glue protectors when the perimeter adhesive deteriorates.