Okinawa Goju-Ryu means "hard-soft school", it is one of the main traditional Okinawan styles of Karate, featuring a combination of hard and soft techniques. Both principles, hard and soft, come from the famous martial arts book used by Okinawan masters during the 19th and 20th centuries, the Bubishi (Chinese,pinyin). Gō, which means hard, refers to closed hand techniques or straight linear attacks; ju, which means soft, refers to open hand techniques and fluid circular movements. Okinawa Goju-Ryu incorporates both circular and linear movements into its curriculum, combining hard striking attacks such as kicks and close hand punches with softer open hand circular techniques for attacking, blocking, and controlling the opponent, including joint locks, grappling, ground techniques, kicks, strikes, punches, takedowns, and throws.
Major emphasis is given to breathing correctly in all of the katas but particularly in Sanchin Kata which is one of two core katas of this style. The second kata is called Tensho, which is meant to teach the student about the soft style of the system. Okinawa Goju-Ryu is a practical martial arts and practices methods that include body strengthening and conditioning, its approach to fighting involves distance, stickiness, power generation, fluidity, technique, and partner drills.
Okinawan Goju Ryu Karate training takes place in a formal atmosphere with an emphasis on etiquette and self-control as well as physical ability. Training generally is divided into the practice of defence techniques, sparring, basic drills, conditioning and kata. Within sparring, students stop blows just short of contact so that power is always maintained with control especially for children.
For more information on Okinawa Goju-Ryu you can buy or Warriors Training Handbook which covers the history and the art form in more depth.