Witchcraft is the art or practice of manipulating and channeling energy with one’s intent/will in order to achieve a goal or manifest a change in one’s life. The art can involve prayers/spells, rituals, use of herbs, crystals or sigils, following the lunar calendar and many other traditions.
Witchcraft is a secular practice, which means that it is not related to religion. It’s neutral, being neither “bad” nor “good” exactly like gardening, knitting or any other professional skill or hobby. It is what you make out of it and thus can be really individual. Every witch has their own ethics and beliefs, thus it can also be religious and/or spiritual, but it doesn’t have to.
Here some interesting links: