[Simple question. How do I remove deleted "phantoms" from picture]

Thank you!!!

[Simple question. How do I remove deleted "phantoms" from picture]

Hello,

This is such a basic question for a completely new user to any kind of design program, but it's driving me up the wall.

After I delete a layer it still shows on my main picture with dotted lines. How do I actually clean my picture so that the dotted lines that look like a selected image disappear?

I've been looking for a bit now and don't even know how to pose the question to search for an answer.

Thank you in advance.

I'll post a picture of what I mean. It's probably the most basic of things.