Microblading
A semi-permanent tattoo that draws fine hair-like strokes into the brows with a hand tool.
Also: brow embroidery
Microblading uses a small hand tool with a row of fine needles to scratch pigment into the upper skin in strokes that look like brow hairs. It became widespread in East Asia and then worldwide in the 2010s. The marks fade over one to three years. Because it breaks the skin, it is a form of tattoo, and health rules in many places require licensed practitioners. It is a cosmetic choice, not a necessity.