Think about the tasks your knife will perform. If you will use it mainly for cutting fruit or whittling sticks, a plain edge will suit your needs since it is for push cuts and slicing. It is great for cutting softer materials and easy to sharpen. A serrated edge, however, is better for pull cuts, such as cutting a rope. It is for cutting tougher materials that need a bit of sawing. Serrated blades hold their edge longer, but you have to use special tools to sharpen them. Sometimes you can get a blade with a partially serrated edge. This combo type usually comes with the serrated part toward the handle and the plain one near the tip, but with some knives, such as the Swiss Army Victorinox One-hand Trekker, this order is reversed. Therefore, you can choose the knife with the edge that best suits your tasks.