<p>In the theory of plate tectonics, plate margins are the tectonic domains where relative plate motions and interactions are most intense, and the relevant processes have already become the core components of the plate tectonics theory. During tectonic processes, either from seafloor spreading to oceanic subduction or from continental collision to post-collisional reworking, transform faults can appear in all plate tectonic processes involving lateral motion. At convergent plate margins, oceanic plates can subduct into the deep mantle, whereas continental plates can only subduct into the shallow mantle. The development of divergent plate margins involves either aborted or successful continental rifting; if successful, continental breakup is followed by seafloor spreading. Therefore, plate margins are the most active tectonic belts on the solid Earth, controlling the exchange of material and energy between the crust and the mantle. Research on the structure, composition, and dynamics of plate margins can not only accurately depict the formation and evolution of intracontinental orogenic belts but also effectively constrain the operating mechanisms of plate tectonics. Understanding the formation, evolution, and dynamics of plate margins fundamentally requires determining the structure and composition of plate margins. By a systematic review on results on transform faults, mid-ocean ridges, continental rift zones, oceanic subduction zones, continental collision zones, and intracontinental orogenic belts, it is evident that plate tectonics theory has made remarkable progress in the 21st century and has essentially completed a series of paradigm shifts in conceptual frameworks: transform faults have moved from conservative boundaries toward complex systems, continental collision has progressed from a progressive to a non-progressive model, and intracontinental orogenesis has shifted from plate-margin affiliated to an independent dynamic mechanism. However, alongside theoretical innovation, deep-rooted problems have also been exposed, such as insufficient empirical support, disconnection between dynamic simulations and geological observations, and declining predictive power caused by conceptual generalization or oversimplification. Therefore, future breakthroughs need to embrace complexity while pursuing simplicity, move from explaining the past to predicting the future, and establish tectonic evolution models from plate margins to continental interiors.</p>