A townhouse is a home that shares one or two walls with the houses next to it, standing in a row like books on a shelf. Unlike an apartment where families live stacked on top of each other, each townhouse has its own front door at street level and usually includes multiple floors inside.

Townhouses became popular in crowded cities where land was expensive. Instead of spreading out with yards on all sides, builders constructed homes that touched each other, allowing more families to live in a smaller area. Many historic townhouses from the 1800s still line the streets of cities like Boston, Philadelphia, and San Francisco.

Modern townhouses combine some benefits of both houses and apartments. You might have a small yard or patio, but you won't need to maintain as much outdoor space as a standalone house requires. You'll share walls with neighbors, so you might hear them occasionally, but you won't have people living above or below you, as in an apartment building.

The term can also refer to elegant city homes owned by wealthy families, especially in historical contexts. A wealthy family in Victorian London might have owned a townhouse in the city and a separate country estate for the summer.