A barrio is a Spanish word that means "quarter" or "neighborhood". It is generally defined as each area of a city, usually delimited by functional, social, architectural, or morphological features. In Spain, several Latin American countries, and the Philippines, the term may also be used to officially denote a division of a municipality.

In the United States, a barrio is a neighborhood where most people speak Spanish, especially in crowded inner-city areas. For example, Spanish Harlem in New York City is also called El Barrio. In some cases, a barrio may have a distinct character from other areas, even if it has been superseded by larger administrative divisions.

The term "barrio cerrado" is used in some countries to describe small upper-class residential settlements planned with an exclusive criterion and often physically enclosed in walls, similar to a gated community.

In Colombia, the term "barrio" is used to describe any urban area neighborhood whose geographical limits are determined locally, and it can refer to all classes within society. The term "barrio de invasión" or "comuna" is more often used to refer to shanty towns.

Overall, a barrio is a term used to describe a neighborhood or district of a city, often with a distinct cultural or socioeconomic character.