Wtf is a caliper bushing?

I always used Sil-Glyde and tossed every anti rattle anything I come across. I bought a giant tube of Sil-Glyde years ago and use on all types of stuff. I'm probably still only 1/3 into it.

I was always told silicone grease wouldn't contaminate pads or shoes if it got on em. Is that brake lube the same stuff?