Mathematically, folding refers to a new line segment obtained by folding a line segment on a plane. Specifically, if a line segment is folded in half along one point, a new line segment is obtained, and the two endpoints of the new line segment are the positions obtained after the two endpoints of the original line segment are folded in half. This process is called folding.

In daily life, folding is widely used, including folding paper into various graphics and making folding models of buildings. In mathematics, folding also has many applications, such as using folding to solve geometric problems. In some math exam questions, folding is also one of the frequent questions.

Folding is of great significance in mathematics education. Learning the method of folding is helpful to cultivate students' spatial imagination and creativity. At the same time, folding can also help students understand some mathematical concepts, such as symmetry and similarity. Therefore, related courses and activities are often arranged in school mathematics education.