What is the 2016 South China Sea ruling over which China tried to bully Philippines?

The 2016 South China Sea arbitration ruling had declared China’s 'Nine-Dash Line' claim in the South China Sea as legally invalid. The tribunal found that China encroached on the Philippines’ sovereign right by constructing artificial islands and interfered with the country's petroleum exploration. China had declared the judgement "null and void" and tried to nullify its impact through coercion.