Does the server have nginx and is it working?

Question

Nginx

Command: ps -ax | grep nginx
25689 pts/1 S+ 0:00 grep --color=auto nginx
Command: service nginx stop
Failed to stop nginx.service: Unit nginx.service not loaded.
Command: nginx -v
nginx: command not found
Can't figure it out, I don't have nginx? Why is grep not empty then?

Answer 1

Why is grep not empty then?

grep found itself.