Zhou Yi, Yijing or I Ching

Zhou Yi is the original core of the I Ching also written Yijing
Zhou Yi is pronounced djow-ee
I Ching is pronounced: ee-djing

Zhou Yi is the oldest known name for this text. It was mentioned several places in the ancient historical text Zuo Zhuan, which was written around 400 years B.C.E.
Over time many commentaries has been appended and associated with the original divination manual. This collection of text from different unknown authors are called
I Ching – The Classic of Change.

In the countless translations and books on the I Ching authors have mixed lines from various commentators with the original core without making it clear that these parts does not belong to the original divination manual

To avoid confusion and to make it clear what is the original core I, and many others, call the original core text by its oldest name—The Zhou Yi— which means
The Book of Changes from the Zhou Dynasty.