St. Dominic founded a branch of the Order of Preachers for women as well as one for men: in addition to the friars who imitated St. Dominic’s synthesis of contemplative prayer and apostolic preaching, many women followed in the contemplative footsteps of St. Dominic by becoming cloistered nuns at the monasteries established by St. Dominic and by others in the succeeding decades and centuries. Several centuries after St. Dominic’s lifetime, however, a new form of Dominican life for women began to emerge which included the opportunity for active apostolic work in addition to a life of prayer and community. While never replacing the contemplative, cloistered female branch of the Dominican Order, this new mode of active Dominican apostolic life for women grew in breadth over the course of the centuries.
Over time, two special focuses emerged for congregations of Dominican sisters: many sisters focused on the spiritual works of mercy, engaging in a teaching apostolate, whether in grade-schools, high-schools, or colleges and universities; others focused on the corporal works of mercy, serving as nurses or doctors or in a variety of other ways. Today, a large variety of congregations of Dominican sisters serve throughout the world. Each congregation is independent of the others, but is “affiliated” with the Order of Preachers by means of the approval of the Master of the Order. Each congregation has a distinctive history and traditions, but participates in the great heritage of the whole Order of Preachers.
— Fr. Innocent Smith, O.P.