Safety wiring grips

I hear a lot about safety wire to wire grips on, but what exactly is safety wire? Do i go to my hardware store and ask for safety wire? I thought its probably just wire, but what type and size wire do i use?

[PsychoDave]

i think it is 22 gauge wire....(not to thin but not too thick)....i use it. my grips never move!!!!!

Ive got em to....I think that they make the grips feel better..I bought a kit at the dealer around here and came w/ a little twister thing that twisted em on there good