Why is there still the moon during the day?

The reason why there will be a moon during the day:

1, the moon can be seen in the daytime with different brightness, probably because of the different brightness. Every morning or evening, when the sun rises or sets, the brightness is low and the blue sky can't cover the moon.

2, the sun and the moon can see the moon during the day, which may be the phenomenon that the sun and the moon shine together. The period for the earth to revolve around the sun is one year, while the period for the moon to revolve around the earth is 27 days.

3. The shape of the moon will change constantly within a month.