Rochester is a city in the U.S. state of New York, the seat of Monroe County, and the fourth-most populous in the state after New York City, Buffalo, and Yonkers with a population of 211,328 in 2020. The city of Rochester forms the core of a larger metropolitan area with a population of 1 million people, across six counties. The city was one of the United States' first boomtowns, initially due to the fertile Genesee River Valley, which gave rise to numerous flour mills, and then as a manufacturing center, which spurred further rapid population growth.
Rochester rose to prominence as the birthplace and home of some of America's most iconic companies, in particular Eastman Kodak, Xerox, and Bausch & Lomb, by which the region became a global center for science, technology, and research and development. This status has been aided by the presence of several internationally renowned universities and their research programs; these schools, along with many other smaller colleges, have played an increasingly large role in Greater Rochester's economy.