This is bcoz moon takes rays from sun or rays of sun r reflected to moon so it looks bright.
why does not Moon appear bright during day?

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 moon has no light so at night it reflects rays from sun.

why does it appear bright during night and not during the day?
because moon only reflects only a faint light from sun so it appears clearly in night where as in day the reflection of moon light is much less than that of sun so we cant see it clearly