Witchcraft is not religion, but a practice. A practice in which as been done for thousands of years. Another name for Witchcraft is "The Craft of the Wise", back in medievel times many wemon were in practise of this craft, sense some wemon were close to nature, they were able to figure out the magickal healing properties of some herbs.
But what they didn't know, was in the future their kindness to people would turn against them, they started the witch burnings. Now Witchcraft is not a religion but a practice then you are guessing what religion is Witchcraft in? Well in most things I read, I see that Witchcraft is more associated with Wicca.
Most Witches believe in "karma" believing in when you do good deeds you will get good karma. If you do darker deeds, then you will get darker karma.
Witches either work alone or in a group of people which in general we call it a coven. Now Witches usually preform ritual, looking for guidance with spirits, and many other things...they not not different from other religions.