Guarding 守, Gathering 聚, Guiding 行
Three important categories of neigong practice are guarding, gathering, and guiding. These categories describe both the technique and the result achieved by the practice.
Guarding 守
Many have heard the saying “yi shou dantian” meaning attention guards the dantian. This relates to practices derived from the technique of guarding (shou 守) which has deep roots in both Daoist and Buddhist meditation practices variously referred to as shou yi 守一 “guarding the one”, shou zhong 守中 “guarding the center”, and shou qiao 守窍 “guarding the opening.” In this mode of practice, attention is stabilized on a special energetic location in the body such as the various openings or qiao, including the three dantian.
Neigong practices can make use of this technique to activate a particular energetic center in the body, as well as allow the circulation and accumulation of qi to come about in a spontaneous and un-guided manner. In meditation practice, guarding an opening can allow a practitioner to still the mind, unite shen and qi, gather and condense qi into a particular location, and ultimately move into a pre-heaven state of consciousness.
While in neigong practices that involve standing postures and various amounts of motion, the level of stillness needed to access a pre-heaven state is nearly impossible to attain, the technique of stabilizing the mind in a specific location can nonetheless move the practitioner closer to a state of wuwei.
Gathering 聚
While neigong practices that utilize the technique of guarding also accomplish the effect of gathering qi into a particular energetic center in the body, gathering techniques take it to the next level. Gathering techniques may have names like ju qi 聚气 “gathering qi” or cai qi 采气 “collecting qi” (with the latter deriving from the well-known inner alchemy term cai yao 采药 “collecting the medicine”).
In these practices, intentional movement coordinated with awareness and breath actively work to collect qi and deposit into an energetic location in the body, usually the lower field (i.e. lower dantian). In this way, it is possible to build massive amounts of qi at an accelerated rate. These techniques make use of various means and may either amplify the process of taking in qi via the breath and energy fields (qi chang 气场) of the surroundings, or even utilize techniques similar to those used during qi emission (faqi 发气) but in this case instead of emitting qi into another the practitioner is essentially using the methods to collect and deposit qi from their own bodies into a specific location.
Guiding 行
Guiding (xing 行, or dao 导 as in the term daoyin 导引, one of the classical terms for qigong/neigong) is all about intentionally guiding qi along routes within the body, generally using a combination of coordinated intention, movement, and breath. The body contains a network of energetic pathways known as meridians (jingluo 经络). The free and unobstructed flow of qi through these channels has long been associated with an optimally functioning, healthy body, a heightened state of being, and is a major goal of energetic internal arts practices.
Neigong practices that guide qi through the meridians have the effect of enhancing both the meridians and the body’s qi itself. Meridians are unblocked and enlarged, qi is refined and its functions enhanced. Guiding qi through the body’s various energetic anatomy enhances the anatomy itself.
Additionally, the ability to guide and control qi at will is in itself a skill that can be used for various purposes beyond general self-development, such as protection and self-defense, self-healing as well as the healing of others via qi emission. This then brings additional meaning to the term neigong “internal skill.” The terms qigong and neigong can refer both to practice itself as well as the result of the practice (“he/she has a high-level of qigong”). Some neigong lineages distinguish between a mere breathing practice (tuna 吐纳)–which may be used to gather qi or for other purpose, and neigong 内功 (“inner skill”) itself, holding that true neigong involves the ability to guide and circulate qi through the meridians and organ systems. In other words, to call it “neigong” it is not enough to merely have qi, you need to be able to demonstrate the skill of doing something with the qi as well before it can really be considered true “inner skill.”
These categorizations are certainly not exhaustive and I’m sure there are practices that can fit into several or perhaps none of the above categories. That said, I’ve found these categories useful as a way of understanding the what and why of the many neigong practices that are out there.