Originally Posted by: CSchlegelPentatonic refers to any scale with five notes. One can split the intervals in a variety of different ways. The primary ones we use in Western music are major pentatonic and minor pentatonic. See here:

http://www.guitartricks.com/tutorial.php?input=296

Some Oriental systems (and therefore Eastern music) use different arrangements of intervals. See here:

http://www.guitartricks.com/tutorial.php?input=40

While this is 100% right I would like to add that the pentatonic scale also occurs in 5 scalar patterns over the fret board before repeating an octave. While this may be obvious to some, I belive that this information may add some clarity to the definition for others.