Qigong master Ken Cohen calls qigong “a many-faceted jewel”; some of the facets being posture, breathing, awareness/mindfulness, focus, movement, affirmations, sound, self-massage, envisioning the “qi field”, healing others, meditation and so on. When you begin qigong, this gem may be hidden in a very plain-looking stone; some people may instantly crack open this stone and experience the gem within. With everyone, daily practice reveals, “cuts,” refines and polishes this gem, and we are often awed as we experience its growing beauty, power and healing.
“Qi” (pronounced “chee” and also popularly spelled “chi”) doesn't have a precise English translation. The closest we have been able to come is “vital energy,” and it is this energy which manifests in myriad ways on Earth: trees, rocks, clouds, wind, electricity, animal/human bodies. (Some definitions restrict “qi” to only living (breathing) organisms, but I have experienced the broader definition.) The qi is different in each manifestation, and differs also within that manifestation, yet never loses its basic essence--just like water can be steam, rain, ice and ice itself can be hard, soft, melting, snow.
“Gong” (pronounced “gung” as in “lung” and also spelled gung and kung) means “work” or “continued practice.” It is also the goals of practice, the schedule of a practice, and the benefits derived from a persevering practice.
“Qigong”, therefore, means working with this vital energy, practicing daily to cleanse the body/mind/spirit and build a reservoir of qi within the body, and ultimately harmonizing the body/mind/spirit entity.
Qigong has been around for a very long time in China, and, in myriad different forms and with different purposes all throughout Asia (India, Korea, Japan, etc.) For a more complete and comprehensive summary of qigong, see Ken Cohen's website, www.qihealing.com or his book, “The Way of Qigong,” (1999)