The blues scale is pretty much the minor pentatonic scale with the addition of a b5. This single note addition to the scale easily turns this scale into the perfect blues scale for all your blues needs. This is an extremely popular pattern or version of the blues scale.
Scale Patterns are moveable scales where fingerings don't change from key to key. The root note (green dot) names the key of scale. What does this actually mean? It means you simply learn this pattern and you immediately know all 12 keys. You just need to place it on the correct fret to play the scale in a particular key.