What is microfoam and why does it matter for latte art?

Microfoam is steamed milk with very fine, velvety bubbles — almost indistinguishable from liquid, with a shiny, paint-like appearance. It's created by introducing a small amount of air at the beginning of steaming and then integrating it fully. Microfoam pours smoothly and allows latte art because the foam flows with the liquid. Coarse, bubbly foam (macrofoam) creates cappuccino texture but won't pour into art patterns.