What does three-body eto mean?

Three-body eto is the abbreviation of three-body organization of the earth. This is an international organization mentioned by science fiction writer Liu in Three-body.

The famous figures of the European Trade Organization are Ye and Evans. Ye Wenjie is the supreme commander of the earth's three-body organization. As the commander-in-chief of the earth's three-body rebels, Ye Wenjie is just a spiritual leader and does not participate in the specific operation of the organization. She doesn't know how the three-body rebels, which later became very large, developed, or even the specific number of organizations. Evans is the actual founder of the earth three-body organization. He is a staunch believer of the Adventists, from disappointment to hatred, and finally to hatred. He is the main contact between the earth three-body organization and the three-body person.