We promise it doesn’t hurt! In regards to printing, a bleed is set up prior to printing. It requires that the document be printed on a larger page size to allow an image to extend off of the final edge. After the document is printed it is cut to the final size with your image extending off of the page.
When designing a bleed it is standard to set up the document with an 1/8th inch of extra page. Be sure that the images you want to bleed extend our to the edge of the document, past its guidelines. The bleed gives the appearance that the image “bleeds” off the edge of the paper.