What is Wicca? 

This is a very big question.

Wicca is a nature-based religion. Many Wiccans call themselves Pagans, though this may be true for some, in most cases this is not true. Pagen means country dweller. All Wiccans are Witches, and most belief in witchcraft. There is no centralised organisation in Wicca. The beliefs and practices of Wiccans can vary, but the principles and ritual structures are shared. At initiation, some Wiccans adopt a craft name to symbolise their spiritual "rebirth".

Witches do not worship the Devil or Satan. Witchcraft predates Christianity and does not believe in the Christian Devil.

Wicca:

• Is a polytheistic religion, typically focusing upon dedication to a God and a Goddess.
• Is a modern religion influenced by a variety of pre-Christian beliefs.
• Teaches that we all are ultimately responsible for our own actions.
• Views the spiritual and material worlds as overlapping.

To answer this question better, I have made several sections to go more into detail for you.