Understanding Page Layout
Everything within the bleed area (0.125" / 3mm) with be trimmed. However, you should extend your image to the edge of this area for a full page design without border.
Leave minimum 0.39" / 10mm width of border if necessary.
Anything inside this area is safe, so you will want to keep all your important content here.
This is the crease or the center folding line of the album. Avoid placing human facial features and text across this line.