covens

A coven is a working group of Witches. Some people believe that the coven was an invention of the Inquisition. Because the Inquisitors saw Witchcraft as a parody of Christianity, they decided that Witches be organized in the same way that Chrisitan monks were. At the time, monks were grouped into "convents" of 13 in honor of Christ and 12 apostles. Other people believe that witches have worked in covens since time immemrial. Either way, modern covens do exist, and they work.
Covens usually have one or two leaders who are known as High Priestess or High Priest. The number of Witches in a coven run between 3 and 20. Some covens keep their membership to 13 or fewer because 13 people is the largest number you can comfortably accommodate in a nine foot circle, a sixe that is considered traditional by some witches. Covens perform magick together and engage in religious rituals, according to the tradition that they follow. Every coven is autonumous. So, each coven gets to make it's own decisions.
In a coven, you get alot of support. You have people available to you who have more education in the Craft then you do, so you can learn from them. There is camaraderie in a coven. You also get some structure in terms of schedule and how you go about learning the Craft. Within the coven structure, you can work up to higher degrees, eventually attaining the rank of High Priestess or Priest. The teachings of a coven have been handed down through a lineage- which is important to some people.
That fact that there is structure in a coven can be a con for some people. The coven will make decisions about meeting times attendance that might not fit your busy schedule. Covens have certain expectations of each and every member that you may not be comfortable with. Maby covens have dress or (undress) requirements that you might not like.
If you break the laws of the tradition of your coven, your coven and it's community can oust you. If you leave the tradition and go to another tradition, you may have to start your training all over again as if you had never been trained at all. There are many traditions that will not recognize the degrees granted by covens of other traditions.