Why are there multiple process, e.g., diff PIDs, of user 200 running?

I have a Ubuntu 18.04 host running exclusively a Nexus 3.x server, which I start via this command.

docker run --rm -d -p 8081:8081 -e INSTALL4J_ADD_VM_PARAMS="-Xms6G -Xmx6G -XX:MaxDirectMemorySize=15530M" --name nexus -v nexus-data:/nexus-data sonatype/nexus3

WhenI do htop on the host, I see multiple processes, e.g., diff PIDs, for user 200. Is this normal?