Today , the city is an international hub for finance , commerce , industry , technology , telecommunications , and transportation , with O'Hare International Airport being the second-busiest airport in the world ; it also has the largest number of U.S. highways , and railroad freight entering its region .
The city is an international hub for finance , commerce , industry , telecommunications , and transportation , with O'Hare International Airport being the second-busiest airport in the world in terms of traffic movements .