Light rays that are parallel to the principal axis of a concave mirror converge at a specific point on its principal axis after reflecting from the mirror. This point is known as the principal focus of the concave mirror.
Use of convex mirror:
Used inside buildings such as large offices, stores, and hospitals to see people around the corner so as to avoid accidents.
Used as a rear-view mirror in vehicles and automobiles.
Used for security purposes in many places such as ATMs.