How to know name of program running at a port code example

Example 1: check which application is using port

In Windows CMD/Powershell:
netstat -aon | findstr '[port_number]'

Example 2: cli check what is listening on port

lsof -i tcp:53 #Check what is listening on port 53
lsof -t -i tcp:53 #Return the process PID listening on port 53