How would make I Proxy meshes?

I was thinking about making a rig, and a proxy mesh, but I don't know-how.
it says a proxy file. How would make a proxy file?
it says a proxy file. How would make a proxy file?
modelling of 3-Dimensional characters
http://www.makehumancommunity.org/forum/
http://www.makehumancommunity.org/forum/viewtopic.php?f=20&t=19759