Pantheism: All Is Divine
Pantheism is the belief that divinity is in everything, that every plant, rock, animal, and person is divine and is inhabited by the divine energy of the universe. This is not to say that every plant, rock, animal, and person is a god. Rather, the gods created these objects and they still harbor the divine energy of the creator.
Pantheism sees everything in the universe as sacred, but that doesn't mean you should approach every object with complete awe and sanctity. The tree is sacred, but its purpose is to create oxygen and wood, and therefore it is not necessarily a violation to take a branch, or even chop it down, if that is part of its purpose, or it has become diseased.
Wiccans vary in their acceptance of pantheism. Some Wiccans do see each object as inhabited by a divine spirit with which they can communicate. This is why you will often hear admonitions to ask a plant for permission before cutting it, and to thank it afterward. Others view living plants as the homes of spirits such as dryads, faeries, gnomes, and other nature creatures.
The system can become rather complicated, even more so when animals are considered. Out of reverence for the sacredness of animals, some Wiccans follow a vegetarian diet. Other Wiccans do not, and see little distinction between killing an animal for food and killing a plant for food. The choice is up to the individual. There is no Wiccan doctrine stating which one is correct.