People often use "New York City" and "Manhattan" interchangeably, but they're not the same thing. Here's the breakdown.
New York City is the entire municipality—population ~8.8 million—comprising five boroughs: The Bronx, Brooklyn, Manhattan, Queens, and Staten Island.
Manhattan is just one of those five boroughs, an island bordered by the Hudson and East Rivers. It's the smallest by land area (22.8 sq mi) but the most densely populated (~72,861 people/sq mi).
| Feature | New York City | Manhattan |
|---|---|---|
| Population | 8,804,190 | 1,664,727 |
| Land Area | 302.6 sq mi | 22.8 sq mi |
| Density | 27,786/sq mi | 72,861/sq mi |
| Boroughs | 5 | 1 |
| Key Landmarks | All of Manhattan's + Brooklyn Bridge, Statue of Liberty | Empire State Building, Times Square, Central Park |
In short: NYC is the whole pie; Manhattan is the most famous slice.