More seriously, for those whose hobbies don't include astrophysics or orbital mechanics, the LaGrange points are five solutions to a specialized three-body-problem setup (the problem being setting up three bodies in a stable orbital system). Joseph Louis LaGrange calculated that in a situation involving one comparatively-massive central body, and one slightly smaller orbital body, there are five points at which a body of relatively trivial mass can be located and have its orbit "held" (more or less) by the gravity of the other two bodies. In the case of the Earth-Moon system, those points are between Earth and Moon (L1), on the far side of the Moon but in a direct line with Earth (L2), directly opposite Earth from Moon (L3), or sharing an orbit with the Moon but sixty degrees ahead of or behind it in orbit (L4 and L5). Of those points, the ones with the greatest librational stability (the ones in which gravity tends to keep the body in its orbit, rather than letting it fall out) are L4 and L5, which is why it has been proposed to place O'Neill colonies in those points. (The stability can be observationally confirmed with the Sun-Jupiter system; its L4 and L5 points are occupied by the Trojan asteroids, leading to these points sometimes being referred to as "Trojan points".)
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Sodium is a metal that reacts explosively when exposed to water. Chlorine is a gas that'll kill you dead in moments. Together they make my fries taste good.