We call this movement "apparent" because the Sun does not actually travel around the Earth. Instead, this visual shift is caused by Earth’s orbit around the Sun. As the Earth moves in its yearly path, our perspective changes, making the Sun appear to "slide" in front of different background stars and constellations. It is much like sitting on a moving carousel: even though the statues in the center are still, they appear to be moving past the background as you circle around them.