Seed - "A pseudorandom number generator's number sequence is completely determined by the seed: thus, if a pseudorandom number generator is reinitialized with the same seed, it will produce the same sequence of numbers."
It is used as a basis to get a specific set of random numbers. The term seed I believe does come from a plant's seed. The same set of random numbers will always "grow" from the same seed.
Permutation - "In mathematics, permutation is the act of arranging the members of a set into a sequence or order"
In construct, a permutation table is a randomized set of numbers that are saved and can be referenced at a later time.
Threshold - "Minimum or maximum value (established for an attribute, characteristic, or parameter)"
Generally speaking, this is a cutoff value at which something takes effect.