Elsevier Computers and Security "With Editor" status just after 12 hours - what does it mean?

I am very new to research, I work as a research assistant at the University in Sweden for 3 months. Yesterday, at 5 pm o clock (my local time) I submitted a paper to Elsevier's Computers & Security. My paper got status "Submitted to Journal", which was fine.

Today, at 6 am o clock (my local time), I got an email, that my paper changed its status to "With Editor". As I wrote, all of this is very new to me, and I do not understand that - does it mean that someone is working on my paper just now? So fast? Does it mean my paper has good or bad quality? Could somebody please explain this?