I just want to ask about description of the project: Autonomously governed decentralized digital asset exchange. Is "autonomously governed" not have the same meaning as "decentralized"? What is the difference?
There is quite a difference! The Wyvern Exchange is governed by the Wyvern DAO, which controls a large share of WYV tokens and can upgrade the Exchange smart contracts. This means you - as a protocol shareholder - have a direct say in the future of your protocol, and it (hopefully) will enable Wyvern to incorporate the best new ideas over time.
You can read more on the first protocol upgrade discussion at
https://github.com/ProjectWyvern/WDPs/issues/6.