Diurnal Motion

Diurnal Motion is the motion that stars, the Sun and the Moon appear to make around the Earth from our observable point of view. The motion is in consequence to the rotation of the Earth.

Example
When looking directly above you on the East Coast of the United States of America at a certain time, it is possible to see the Cygnus Constellation. Four hours later, the entire sky appears to have rotated to the west. Now at midnight, it is possible to see the Andromeda Constellation. This shows the Diurnal Motion as it happens.