This is an drawing of the earth and an image of Uranus. Image from: The Atmosphere, 5th edition

In this picture, the Earth and Uranus are both viewed from the top. In the picture of the Earth, the sun is shining from the side. The picture shows that part of the north pole is in daylight and part of the north pole is in darkness. This is because Earth spins (in 24 hours) at right angles to the sun's rays, and for 12 hours half of the earth is dark.

Unlike the Earth, Uranus spins (in 10 hours) with the north pole facing the sun. So, in the picture, the north pole of Uranus is never in the dark. This means that daytime on Uranus lasts for a long time.