Yes: They are exactly the same thing. “Qigong” is the current method of writing (romanizing) the Mandarin pronunciation of the characters 氣功, while “chi kung” is an older spelling still used in some parts of the world. However, qigong and taiji (also spelled “tai chi“) are two different things. Taiji is a style of internal (which means it usually looks slow) style of Chinese gong fu (kung fu), while qigong is a discipline focused on using body breath and mind to develop and circulate internal energy. While taiji has been the subject of dozens of health and longevity studies and its benefits are widely known, those benefits are even more substantial and tailorable in the practice of qigong, due to the close association between qigong and Chinese medicine.