1 Axisymmetric: If a graph is folded in half along a straight line and the two parts completely overlap, such a graph is called an axisymmetric graph, and this straight line is called an axis of symmetry. ; At this time, we also say that these two figures are symmetrical about this line. Such as a circle, a square, etc.

2. Central symmetry: ② Central symmetry: If a graph can overlap with another graph after rotating 180 degrees around a certain point, then we say that these two graphs form central symmetry. For example: rectangle, diamond, square, circle, etc.

Note: Axial symmetry and central symmetry refer to one figure (graphic feature), while axial symmetry and central symmetry refer to two figures (positional relationship).