Docker Compose is a tool that simplifies the process of creating and running multi-container applications by automating the management of multiple Docker containers simultaneously. It allows users to define their application's containers as code inside a YAML file, which can be committed to a source repository. This makes it quicker, easier, and more repeatable than manually starting and linking containers. Compose also automatically creates a Docker network for the project and manages storage volumes. It is particularly useful for applications with multiple services that have dependency relationships or require specific configurations before deployment.