Okay, I think you mean arpeggios, not arcapegios or whatever. They are just chords that are played broken up, rather than strummed. Like playing them one note at a time.
As for the pentatonic scale, there are two kinds, minor and major. They are both five note scales that are derived from the major and minor scale.The major pentatonic is like a major scale without the fourth and seventh notes. The minor pentatonic is taken from the natural minor scale, and is missing the second and flatted sixth notes.
The formula for major is 1 2 3 5 6, and 1 b3 4 5 b7 for minor.