What's the difference between the Eight Diagrams Mirror, concave mirror and Convex Mirror in Feng Shui? How to put the Eight Diagrams Mirror?

Concave mirror is used to eliminate evil spirits, such as arm knives, road rushes and diagonal lines in the sky. Concave mirror can be used to eliminate pathogenic factors, but it is best to use plants or water, and plants have a better effect of eliminating pathogenic factors. Then there is water, where there is water, qi will gather, so the evil spirits will stop when they reach the water, so harmful evil spirits will hurt the house.