Lagrangian points

[Burning Zeppelin]

So much stuff I read includes these points, but I still don't understand what it actually is. I've read a lot into it (Wikipedia), but still to no avail.

Help?

[Hadriel]

Suppose you have two bodies in space.  A Lagrangian point is anywhere you can put something else that will theoretically allow it to remain in the same position at all times relative to those two bodies (taking into account orbits, gravity, etc.).

[Burning Zeppelin]

Ah, now I think I get it. For some reason before I thought it meant it will stay in the exact same position. Weird. Thank you Hadriel!

So how come the Earth has 5 Lagrangian points?

[Ramsus]

http://www.physics.montana.edu/faculty/cornish/lagrange.html

There's five of them, because every interesting looking chart or diagram needs at least five points to draw shapes and lines around.

Someday I'm going to buy Lagrange points L4 and L5 and start a massive storage/low-cost housing business.