Wicca is a religion created in the 1950s by Gerald Gardner. He then released the 161 Laws, many of which were promptly ignored even by Gardnerians, and eventually by Gardner himself, to some extent. This was certainly justifiable, since the laws themselves stated that they were 'guidelines to help Wiccans' or something of the sort.

Later on, people began to ignore more important traditions: the traditions that made Wicca what it was. People somehow got it into their heads that a lineaged coven wasn't necessary to call oneself 'Wiccan,' and it all went downhill from there.

Wicca was originally a Mystery religion. Even when people were able to openly admit that they were Wiccans (it's theorized that Wicca may actually have been created in the 1930's. There were anti-witchcraft laws in England up untill the 1950's. Allow me to take this moment to say that Wicca is NOT and ancient religion. There are ancient pagan religions, yes, but Wicca only has superficial connections, like holidays), Wicca was still a Mystery religion. Why?

Because the core teachings of Wicca were kept secret, and could only be revealed through the coven.

But I guess people got sick of having to work for the title 'Wiccan.' So they decided that they would be 'Solitary' wiccans and decide that they were Wiccans even when they didn't know much about Wicca besides the basics. Frankly, there isn't much about Wicca that was released: the Rede, the Elements, the Threefold, a few other things. Not a whole lot of research involved.

It's my opinion that 'Solitary' Wiccans aren't Wiccans at all. Frankly, I call them 'Neo-pagans.' After all, the word 'Wicca' was first used by Gerald Gardner to describe a religion, though it does have old roots. Calling yourself 'Wiccan' when you're not following Gardner's religion is like calling yourself Christian when you don't follow Christ's religion.

Obviously, it's not satanism: the deities involved are a God and a Goddess. Contrary to popular belief, the 161 Laws put the God on an equal (maybe even more than equal, by some interpretation) footing with the Goddess.

HOWEVER: Witches can be Satanists. 'Witch' is not interchangable with 'Wiccan.' Witchcraft is not a religion: it's a practice. It's any practice that involves magic. Since many Satanists believe in and practice magic, they can, in fact, be called Witches.