What is the difference between Taoism (Daojiao) and Daoist philosophy (Daojia)?

Lu Xun famously said: "The root of Chinese culture lies entirely in Taoism." In practice, the two are inseparable throughout Chinese history. The Tao Te Ching and Zhuangzi are both philosophical classics and core religious scriptures.

Daojia is a philosophical school; Daojiao is a religious organization. Daojia, represented by Laozi and Zhuangzi, emerged in the Spring and Autumn/Warring States period (6th-4th century BCE) as a philosophical system of thought. Daojiao formed in the late Eastern Han Dynasty (2nd century CE), deifying Laozi as Taishang Laojun and integrating Daoist philosophy, immortality arts, Yin-Yang and Five Elements theory, and folk beliefs.

An analogy: Daojia is the theory, Daojiao is the practice. Daojia provides a worldview and philosophy of life; Daojiao transforms this theory into a religious cultivation system. It is similar to the relationship between Buddhism as philosophy and Buddhism as religion.