* Earth's Rotation: It takes approximately 23 hours and 56 minutes for Earth to complete one full rotation on its axis. This is called a sidereal day.

* Solar Day: However, we experience a solar day which is closer to 24 hours. This is because the Earth is also revolving around the sun. By the time the Earth has completed one full rotation, it has also moved slightly in its orbit. To catch up and face the sun again, it takes an extra 4 minutes.

So, in short:

* The time it takes Earth to spin once is a sidereal day, which is slightly shorter than a solar day.

* We experience a solar day, which is closer to 24 hours, due to Earth's movement around the sun.