On my Lubuntu 22.04.4 LTS x86_64 machine, I have Docker installed and it’s using the socket:

stephane@stephane-20jts0cv0v:~$ ps -aux | grep dockerd
root      255997  0.2  0.7 2282800 60256 ?       Ssl  mai25   9:25 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

But I’m surprised to see it exposes two ports as well:

stephane@stephane-20jts0cv0v:~$ sudo netstat -tunlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp6       0      0 :::2377                 :::*                    LISTEN      255997/dockerd      
tcp6       0      0 :::7946                 :::*                    LISTEN      255997/dockerd

I thought the communication could be handled by the socket only.