This is a nice start to the Lagrange figure. There are Lagrange points that are small and unstable. Also, there are Lagrange areas that are vast and stable. Each planet has this situation going on with the sun, but also each moon with its planet. This means mars has lagrange points and areas with the sun, and the moon also has lagrange points with earth, and so on.
One might easily ask what’s the meaning of all this. Well, the point is simple. This is where to build large things in space. The stability drastically decreases station-keeping fuel, mitigates various risks inherent with space, and has other advantages.
To be more blunt: The Earth-moon Lagrange 4 and 5 are very important locations. They’re where people would live in space if there were lots of them, a great many of them.