They are fixed points of the circular restricted three-body problem.  The first three are unstable to radial perturbations but the final two are in islands of stability.  The SoHO spacecraft orbits on
They are fixed points of the circular restricted three-body problem.  The first three are unstable to radial perturbations but the final two are in islands of stability.  The SoHO spacecraft orbits one in the Earth-Sun system, and for ten points, two in the Earth-Moon system are likely sites for space colonies built at what points named for a French mathematician.
They are fixed points of the circular restricted three-body problem.  
Lagrange or Lagrangian points