Qigong practice involves moving meditation, coordinating slow-flowing movement, deep rhythmic breathing, and a calm meditative state of mind. People practice qigong for recreation, exercise, relaxation, preventive medicine, self-healing, meditation, self-cultivation, and supportive training for martial arts.
Neigong exercises that are part of the neijia tradition involve cultivating physical stillness and or conscious (deliberate) movement, designed to produce relaxation or releasing of muscular tension combined with special breathing techniques. The fundamental purpose of this process is to develop a high level of coordination, concentration and technical skill that is known in the martial arts world as neijin (內勁). The ultimate purpose of this practice is for the individual to become at one with heaven or the Dao.
Practices associated with the word Qigong often have more to do with the study of Qi and the external changes, The use of the word Neigong is often associated more with the inner alchemical changes. Both are intertwined, it just depends on how deep you want to travel or the requirements of the system you study. Shifu Neil Ripski once said "Qigong changes your body, neigong changes your character".
Essential differences between Qigong and Neigong are that Qigong works from the outside to the inside while Neigong works from the core and spreads outwards. Qigong is like acupuncture where specific qigong movements works to clear certain affected meridians.
Neigong works simultaneously from the core on all meridians. Neigong emphasizes more on body, qi and spirit and the three treasures of Jin, qi, shen 精气神 Commonly neigong is more difficult to practice and is considered as advanced and most practitioners start with the easier forms of qigong. Examples of neigong forms are Zhan Zhuang, Bagua Neigong and various Taoist alchemy meditation methods.