You may not always want to simply view the logs of a container; sometimes you want to know what processes are running inside a container. That's where the container top command comes in. Ideally, each container is running a single process, but the world is not always ideal, so you can use a command such as this to view all the processes running in the targeted container:

# using the new syntax
# Usage: docker container top CONTAINER [ps OPTIONS]
docker container top web-server

# using the old syntax
docker top web-server

As you might expect, the container top command is only used for viewing the processes of a single container at a time.