Microservices are about splitting code into different servers instead of a monolithic codebase. You end up with different servers (probably virtualized) for each domain of the application.

Like, instead of having the video decoding and the analytics code in the same monolith attached to same DB, you deploy a different server for each one, generally with a new DB for each. When the services need to talk to each other, they do it via network (REST, gRPC, etc.).