Lagrange points. Named after Italian mathematician
Joseph-Louis Lagrange.
Lagrange points are a solution to what's called the "three-body" problem.
Two massive objects like the Earth and the Sun create points in space
where their gravitational forces balance with the centripetal force
of the motion of a smaller third object - like a spacecraft.
There are five different points where these forces balance named L1 through L5,
L4 and L5 are known as stable points, and they attract objects,
like space debris, which can easily stay in orbit around these points.
L1, L2, and L3 are known as semi-stable.
To stay put here, an object, like a spacecraft,
would have to use some fuel so it doesn't drift off.
We use L1 and L2 between the Earth and the Sun
to host satellites and telescopes without needing an excessive amount of fuel.
For example, the James Webb Telescope orbits
in L2 on the opposite side of the Earth from the Sun.
Lagrange points are a helpful resource in furthering space exploration.