@Yon in it’s simplest form, it’s a local coordinate system for a given triangle, so like where (x, y, z) is your position in Cartesian space, (u, v, w) could be your position in barycentric coordinates, where `u + v + w = 1` meaning as long as your u,v and w are all positive and sum to 1, you’re inside the triangle somewhere
giving you an easy way to interpolate values on triangle vertices