Thank you for your question.
Really, the major difference is as simple as saying that one group is made up of women and the other made up of men. Sisters and Brothers in the church live a similar lifestyle (in a Community), take similar vows (Poverty, Chastity, Obedience), pray in similar ways (together and privately), are involved in similar ministries (education, health care, working for the poor and disadvantaged), and have similar ministries (teachers, nurses, doctors, lawyers, social workers, cooks, secretaries, counsellors, spiritual directors, university lecturers, theologians, etc, etc).
They bring to all these areas, though, a certain style / spirit / charism, coming from their particular Founder / Foundress. And so, each Religious Order, whether male or female, has a certain way of going about things, a certain 'feel' to it, that makes it slightly different to every other Religious Order in the Church - making each Order special and unique and a gift to the whole Church. I hope this answer helps to make things clearer.
You might like to visit our website www.ozvocations.catholic.org.au, and find out more about thie different orders of sisters and brothers in Australia.