# How do I find out what tool a shortcut is triggering?

I used to have problem with connecting two objects, because when I smooth the final object, there was a darker line on the connected parts (for example when I was making head, I've had eyes darker this way). Then I found out that I can get rid of it by hitting Ctrl+N, but I don't realy know what it does. I can just see that the lines are gone. So, what does Ctrl+N do?

• You might be interested in this comment. Dec 20 '14 at 15:20