A video game publisher is a company that publishes video games that have been developed either internally by the publisher or externally by a video game developer. They often finance the development, sometimes by paying a video game developer (the publisher calls this external development) and sometimes by paying an internal staff of developers called a studio. The large video game publishers also distribute the games they publish, while some smaller publishers instead hire distribution companies (or larger video game publishers) to distribute the games they publish.
Wikipedia