What is the territorial dispute over Scarborough Shoal between China and the Philippines?

The Scarborough Shoal is a strategic triangular chain of reefs and rocks located 240km west of the Philippines' main island Luzon and nearly 900km from China's Hainan. China forcibly seized this territory from the Philippines in 2012, despite its proximity to Philippine shores. Recently, tensions escalated when a Chinese navy helicopter flew dangerously close to a Philippine surveillance aircraft carrying journalists over the disputed area. Despite a 2016 international ruling invalidating China's sweeping claims to the South China Sea, Beijing continues its aggressive expansion in the region, leading to repeated confrontations with Philippine vessels resupplying Filipino fishermen in the area.