Microblading is a manual method of implanting colour into the skin. It creates realistic simulated hair, by mimicking the natural growth pattern of the brow. It heals very very soft and is not appropriate for all skin types or desired looks.
Powder brow is just a different technique for getting colour in the skin. It’s a stronger healed appearance, yet soft and powdery. Long gone are the days of the sharpie magic marker eyebrows.
Often times a combination of both techniques are used to get the best end result for the individual. This will be up to the professional to discuss with you.