Ancient Wisdom for a Modern World
Taoism (pronounced 'dowism') is an ancient tradition of philosophy and religious belief that is deeply rooted in Chinese customs and worldview, although many aim to follow its principles rather than as a religion. Taoism is often taught in the West as an atheist or agnostic philosophy, but in China and Taiwan particularly, Taoism still functions like any conventional religion, and not like an abstract philosophy of life.
Taoist ideas have become popular throughout the world through Tai Chi Chuan, Chi Gung, and various martial arts.
Many Taoist ideas come from other Chinese schools of thought. It's not always easy to draw accurate distinctions between ideas that are fundamentally Taoist and those that Taoism took in from elsewhere, especially Buddhism.
The Tao cannot be described in words. Human language can only give hints that may help the mind to form an idea.
The most important thing about the Tao is how it works in the world, and how human beings relate to it. Philosophical speculation about what the Tao actually is, is less important than living in sensitive response to the Tao.
The most useful words to stimulate an idea of the Tao are found in the Tao Te Ching:
The Tao that can be told is not the eternal Tao;
The name that can be named is not the eternal name.
The Nameless is the origin of Heaven and Earth;
The Named is the mother of all things.
......
There was something undifferentiated and yet complete,
Which existed before Heaven and Earth.
Soundless and formless it depends on nothing and does not change.
It operates everywhere and is free from danger.
It may be considered the mother of the universe.
I do not know its name; I call it Tao.
......
All things in the world come from being.
And being comes from non-being. (form comes from formlessness)?

Visit the excellent BBC website for more detailed information on Taoism