The difference between one-point fixation and two-point fixation of Lego lies in the number of connection points between two objects. When two objects touch each other, one point is fixed on the same plane, which makes them stable, that is, one point is fixed. Two objects touch each other, and two points are fixed on the same plane without overlapping, which makes them stable, that is, the principle that two points set a straight line in mathematics is that two points are fixed.