iPhone make sure you save your 5.1.1 SHSH for when (ios)6.0 drops.why?

[jacksmit]

This website says

If you haven't jailbroken iOS 5.1.1 go get absinthe 2.0.x (link to the right) or redsn0w and jailbreak and make sure you save your 5.1.1 SHSH for when 6.0 drops.

http://thefirmwareumbrella.blogspot.com/

Does anyone know why? I've read about on SHSH but dont quite understand it.

 

[dhlizard]

Hash and APTicket files are required to restore to older firmware versions.
You should save them for every iDevice and every firmware version.
They are unique to each device, use TinyUmbrella to save them.

Google "Caching Apple's Signature Server" for more info.