The minor pentatonic scale can be moved up or down the fretboard, enabling you to play in any key. The key is the central note around which a piece of music is built.
All the notes and chords will relate back to that note in some way, and a phrase will sound finished if it ends on the key note. In the pentatonic scale, the key note is the starting note (indicated on the diagram with a square around the note). Depending on where on the fretboard you start the scale, you can play in many different keys. E.g. at the 3rd fret you get a G minor pentatonic scale, at the 6th fret you get a Bb, minor pentatonic scale, etc. The fingering pattern below shows the C minor pentatonic scale, which is at the 8th fret.