The plant's root system is comprised of primary, lateral, and adventitious roots (ARs). Lateral roots emerge exclusively from existing roots, whereas ARs originate from stem or leaf-derived cells. The progression of adventitious root development is a natural part of a plant's growth, commonly observed in most monocotyledonous species where they establish the primary root system, or in various dicotyledonous plants that reproduce vegetatively. Adventitious rooting holds particular significance in the propagation of economically valuable horticultural and woody species, enabling the cloning of plants and swift establishment of superior genotypes before integrating them into production or breeding schemes. The process of AR development is intricate and influenced by numerous intrinsic and environmental factors, encompassing phytohormones, light exposure, nutritional state, stress responses like injury, and genetic traits. This chapter provides an overview of the latest advancements in research concerning adventitious root formation, with a specific focus on the interplay of key hormones and their interactions, as well as the influence of light, a significant environmental factor.