The planet Uranus’s axis is tilted in a peculiar way.
Earth’s axis tilts at 23.5°; Uranus’s axis tilts at 97.9°, which is at more than a right (90°) angle.
Imagine Earth’s poles being located near the equator.
The planet, however, still rotates around its north-south axis.
Because it is tilted more than 90°, Uranus’s rotation is technically retrograde: from east to west rather than from west to east, as on Earth.
Because Uranus is a gas giant, the planet has varying rotational speeds.
Since Uranus’s axis is tilted more than 90° from the vertical plane, the planet appears to rotate on its side.
Technically, Uranus has a retrograde rotation, in the opposite direction from most other planets