polarization is in which "direction" the light is oriented. like if the light was particles, in the shape of a sheet of paper (long, and very thin). polarization means all sheets are nicely stacked, all long sides showing into one direction. a polarizer would simply look like many parallel lines, only the light-sheets with the right orientation get through.
(explaining for the other readers as well, you may know this already, charley)
polarization-ratio simply is how accurate it is. 100:1 means that one light out of hundret isnt parallel to the others, and would at least be filtered in polarizing optics, and would worst make your complicated setup (holography, interferometry or something) not work properly.
all diodes are always polarized.
he-ne laser tubes come in polarized and non-polarized, for example. the latter have more output (per length). they *are* in fact polarized as well, put not polarizing stab
(yeah! linux crashed, reboot, and firefox remembered what i typed so far! lol)
uhm, yes, not polarizing stabilized. means, the polarizing direction can and will rotate, on jump, by time, warming, looking at it and not looking at it.