Activate layer position rulers (smart guides)

[Azulnauta]

I'm not sure how to put the question but ... once I took one of those pre-made .psd poster files and I started using it when I noticed that when I moved some layer I was given the information that made it easier for me to center it on another layer or to find the center of the image.

How is this help activated?

I can print-screen to show what I want

 

[jkemp]

You might be referring to "Smart guides".

Top Menu / View / Show / Smart Guides

 

[Azulnauta]

That's it! Thank you