Wiggle Vector

Additional Seed: If two nodes have the same value here, they will generate the same random vectors (when the seed is the same). This is like adding another random value to the Seed input.

Seed: Two Random Vector nodes with the same seed will generate the vectors.

Evolution: Animate this input to get random movements.

Speed: The lower this is the faster are the movements.

Amplitude: Selected how far the vector moves in different directions.

For more detailed information for Persistance and Octaves read here: http://freespace.virgin.net/hugo.elias/models/m_perlin.htm