I was mystified by pents when I started on 'em.

Keep practicing and all will become apparent, especially when you try to solo over a I IV VII progression !

I think on reflection pents are the single most useful thing I have learnt about playing the guitar. Learning Bar chords and alternate picking are also up there however I think Pents get the crown !

Most blues is based around a pentatonic scale however the Blues scale has up to two extra notes (depending on who you talk to). Searching for "blues scale" will show you the difference between a pentatonic and blues scale however Id get the scale shapes down first and worry bout nuances later.