Teterboro Airport serves smaller aircraft -- primarily corporate jets. I believe it can handle some pretty sizeable planes on its main runway, but there are no major passenger facilities there to speak of and the big airlines all operate out of the other three NY-area airports.
Teterboro is a small municipality in the northern New Jersey suburbs -- located in southern Bergen County, NJ. The airport occupies most of the borough of Teterboro, which is less than one square mile in size. The 2000 U.S. Census listed a total population of only 18 people for this municipality!