The rotational period of Earth; the time in which Earth rotates around its axis 360 degrees.
One day of sidereal time; the time in which Earth rotates once around its axis, relative to the point of the vernal equinox (about 23 hours, 56 minutes, 4 seconds).
The rotational period of Earth; the time in which Earth rotates exactly 360 degrees around its axis, measured relative to the stars (about 23 hours, 56 minutes, 4 seconds).