the edge is a chip , meaning you plug it in between your wiring harness. Efi is a tune , meaning you upload your stock tune using the Efi hand held part plugged into your truck and then into your laptop .after you have a copy of your stock tune , its then modified and then re flashed into your truck . the nice part is you have an LLY so you can also get (but dont have to )whats called a DSP switch ( 2 or 5 position) that will have either 2 or 5 change on the fly tunes available kinda like the edge . with Efi you will need some gauges . If you go to efilive.com you can download the free software to check it out , but it will only be a demo until you buy and register efi .