Sand aging, defined by time-dependent increases in stiffness and strength over periods ranging from days to months, poses significant challenges in geotechnical engineering and soil science. Despite its relevant implications, the mechanisms driving sand aging remain understood. This review systematically examines sand aging, emphasizing the classification of chemical and mechanical processes involved. Key advancements in chemical aging understanding, particularly the influence of surface chemistry and electrokinetic forces, are discussed. Additionally, the review underscores the critical role of micromechanical modeling, especially discrete element methods, in elucidating particle interactions and aging phenomena. The review also identifies essential directions for future research, notably incorporating particle shape and surface texture into aging models. Hence, this comprehensive resource aims to enhance the understanding of sand aging.