You're on the right track! "Penta" means five. "Tonic" means tone or note. Pentatonic means 'five notes,' of which, there are only five individual notes of the pentatonic scale (in every position.) Breaking the pentatonic into modes means that we start a new shape from each of the five notes - resulting in five different patterns all containing the exact same notes. (That's why there's five shapes, and yes, they all have the same notes.)
What many don't understand, is that unlike the classical modes based upon the major scale, you cannot root most of the pentatonic shapes in a traditional way. Scales, arpeggios, & chords normally require a 3rd and 5th to be functional and make musical sense. The 2nd, 3rd, & 4th pentatonic shapes don't meet this criteria. Only the 1st & 5th shapes (aka, the major & minor pentatonic scales) have the necessary 1 3 5 intervals, which makes them the only two I would recommend learning.
That's the basic theory. If, however, you want to run pentatonic licks up & down the fretboard, then you'll want to know all five shapes so that you can connect them all.