I’ve read that it means it appears to be going backwards but does it?
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If you assume that the Earth is the center of the cosmos, then yes, planets appear to periodically reverse direction and then continue on their previous path, unlike other celestial objects like stars, the sun, and the moon, which trace straightforward arcs across the sky. During those times, the planet is said to be in “apparent retrograde motion.”
Of course, we know now that this is because the planets are not orbiting the Earth, but because they are orbiting the Sun, which is orbiting the Earth (from our perspective). But back in ancient times it was very confusing, and people often attached great significance to the apparent motion.
[Here’s a neat picture.](https://earthobservatory.nasa.gov/ContentFeature/OrbitsHistory/images/retrograde_mars_tezel_2007-2008.jpg)
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