'垫脚石' (diàn jiǎo shí) literally means 'a stone used to stand on to reach higher,' combining 垫 (to pad or support), 脚 (foot), and 石 (stone). Figuratively, it refers to something—or sometimes someone—that serves as a means to advance toward a goal, much like a stepping stone. It often carries a neutral or slightly pragmatic connotation, implying utility in progression, though context can make it sound appreciative ('a valuable foundation') or critical ('used and discarded').

The term appears frequently in discussions about career development, education, personal growth, or historical progress—e.g., early experiences that prepare one for greater responsibility. Unlike purely positive terms like 'foundation,' 垫脚石 emphasizes transitional function: the object is not the end goal but enables access to it. It’s commonly used in both written and spoken Chinese, especially in motivational, reflective, or analytical contexts.