The James Webb Space Telescope will be in orbit in a unique configuration when it reaches its destination at Lagrange Point 2, or L2.
The craft won’t be in orbit around the Earth, as is the Hubble telescope, but will orbit around the Sun at a point which is 1.5 million kilometers (about 1 million miles) past Earth at L2, as illustrated in NASA’s graphic: https://www.nasa.gov/topics/universe/features/webb-l2.html
This orbit allows it to stay in line with Earth as it rotates around the Sun, helping to shield it from the Sun and also maintain communications with Earth.
The NASA website explains: “Joseph-Louis Lagrange was an 18th-century mathematician who found the solution to what is called the `three-body problem.’ That is, is there any stable configuration, in which three bodies could orbit each other, yet stay in the same position relative to each other? As it turns out, there are five solutions to this problem—and they are called the five Lagrange points, after their discoverer. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. The L1, L2, and L3 points are all in line with each other—and L4 and L5 are at the points of equilateral triangles.” That is, the Lagrange points are points of relatively stable balance between the gravitational forces of the Sun, Earth and Moon.
