Docker Compose is a tool for defining and running multi-container Docker applications. It allows developers to define a set of containers, their configuration, links, volumes, and networks in a single file, and then spin them up with a single command.
For example, if you wanted to set up a web application with a database, you could use Docker Compose to define the two containers, their configuration, and the network between them. Then, you could use a single command to start up both containers.