A host galaxy is a large galaxy that contains and nurtures one or more smaller galaxies within its gravitational field. These smaller galaxies are often referred to as satellite galaxies, and they orbit around their host galaxy's center in a process known as galactic cannibalism. The term "host" refers to the main body of something, while "galaxy" is a large system consisting of stars, dust, and gas held together by gravitational forces. In this context, the phrase "host galaxy" specifically describes a larger galaxy that harbors smaller galaxies within its structure.