节理是指由于岩石受力而出现的裂隙，但裂开面的两侧没有发生明显的位移。在岩石露头上，到处都能见到节理。节理按成因，分为原生节理和次生节理两大类。其中原生节理是指成岩过程中形成的节理；次生节理是指岩石成岩后形成的节理。

Joint refers to the crack caused by rock stress, with no obvious displacement on both sides of the parting plane. Joints can be seen everywhere on rock outcrops. According to the cause of formation, joints can be divided into two categories: primary joints and secondary joints, the former refers to the joint formed during diagenetic process, while the latter refers to that formed after diagenesis.