Live Sand, Live Rock

[incoma]

What do these term define exactly. Live as in creature infested or live in bacteria infested. Combination of the two?
Anyone who has made there liverock how much did you use to seed it. How long did it take to seed. Are you seeding it for bacteria or for critters.
Same for livesand can I add a detrivore kit or just get some to seed from another local reefer. Where locally would be good to seed my rock if I make some. Should I buy 5 pounds from each store for diversity. What about sand. How can you tell if rock is good you want lots of colour, critters, lifeforms, or porous dense.
Could I just buy a box of base rock from where? and seed it or do I need all Live from the beginning