What a minor pentatonic scale is
In most practical music contexts, the minor pentatonic scale means the five-note form 1, flat 3, 4, 5, and flat 7. In A, that is A, C, D, E, and G.
Compared with the natural minor scale, it leaves out 2 and flat 6. That focuses the sound around stable tones, with the flat 3 and flat 7 carrying most of the blues, rock, and modal color.