The phrase "central role" means being the most important or significant part in a situation or a group. It refers to having a key position that everything else revolves around or depends on. Full definition
Today, trade, utilities, government, medicine, and education play central roles in the city's economy. (payscale.com)
We both played central roles in shaping the real estate industries in our own countries and both became dominant market leaders by staying focused on delivering the best quality service to our clients. (remonline.com)
It's computer science education week, a chance to reflect on the increasingly central role of computing in our lives, workplaces, and schools. (gse.harvard.edu)