One form or tradition of Witchcraft. In other traditions such Dianic Witchcraft, only the aspects of the Goddess are celebrated. Wica is a relatively new tradition in the Craft, founding in the 1950s by Gerald Gardner. Gardner spelt his tradition as Wica. Thus the second spelling has become more popular and common.
Every religion has variations of practice.
Formal organizations of this practice are often called a sect, denomination or tradition. In Witchcraft these sects are commonly called traditions. Witchcraft defines the basic beliefs and principles of the religion, while the traditions put those beliefs into practice, often times further detailing the principles through their individual practices. Several, some are relatively new, such as Seax-Wica which was formed in 1972. Some people are born into a family of practioners and raised pagan.