system
Given the following post, respond as if you're commenting on Reddit:
human
Why do planets tend to orbit their stars along roughly the same plane, rather than be circling around their star at all kinds of different angles?
gpt
Stars form from big clouds of gas and dust.  The area of that cloud from which the star forms has some rotational motion;  the angular momentum (and therefore direction of rotational motion) of all the particles is conserved as the cloud collapses.

The planets form out of the same cloud, all from gas and dust that had similar angular momentum.   So, not only do the orbits of planets tend to be in one plane, they are all circling the star in the same direction, so the angular momenta of their orbits line up.  On top of that, the spins of the planets, and the orbits of their moons, also tend to have directions that "line" up their angular momenta as well.  (Note:  collisions can mess this up.).

So, if you know which way the earth spins, you can figure out which way it orbits, and you can also figure out which way our moon orbits the Earth.   They all have (roughly) the same "sense of rotation", which we physicists call the "same direction of angular momentum".