Susan #87020 – When I worked in advertising and design many years ago, everything that was printed on a commercial press, had a 1/8″ bleed added to the paste-up board. So if something was going to be 8″ x 10″, the paste-up board would have 1/8″ on each side, so the image area would be 8 1/4″ x 10 1/4″, with a trim of 8″ x 10″. The reason for the bleed is that they can’t be certain the machine will always trim on the trim line, so you add 1/8″ so the color will extend off the edge if the cut is off a bit. If I am printing something at home, and trimming it by hand, I don’t add that 1/8″ bleed because I can be more precise when I am hand trimming it. If you are having it printed with a commercial printer and they are going to have to trim it to size, they will probably want you to have the 1/8″ bleed. But I would really ask the printer! Today they can print photos that are borderless, and even my home printer does a pretty good job of borderless 4×6 prints, that are printed on 4×6 paper and not trimmed.
I hope that helps, and I hope I did not make more confusion!