Why is the flat reflective mirror used while light source come from a lamp while concave mirror is used when light source come from the sun?

A flat reflective mirror is used with a lamp because it reflects light in a straightforward manner, allowing for a direct and uniform illumination of a specific area. In contrast, a concave mirror is employed when the light source is the sun, as its curved shape concentrates and focuses sunlight into a specific point or beam, enhancing brightness and energy concentration for applications like solar heating or lighting. The differences in the source's nature and light distribution necessitate the use of different mirror types for optimal performance.