You don't need both, but I prefer the oil in the pm and/or after a shower, and the balm before heading out. If you only can afford one, I'd recommend the oil. It creates a shine while simultaneously softening the beard and making it appear a shade darker. It's terrific stuff and you only need a dime sized amount per application. I've used both for years, and it's the best thing you can do for your facial hair whether you're rocking stubble or a full blown beard.