A condominium apartment is often referred to as a condo, which is a synonym for this type of dwelling. Another synonym is a flat or apartment within a building that is owned by an individual. Sometimes, a condo is also called a unit. Other synonyms include townhouse and cooperative apartment. These terms are often used interchangeably, but they each have slight differences in ownership and management. Regardless of the specific term used, a condominium apartment refers to a living space that is owned by an individual within a larger building or community that offers shared amenities and responsibilities.