Difference is same as difference between a Mo-ped and a Mack Truck.
The 17 HMR is a rimfire shooting a 17 or 20 grain bullet. The 30-06 is a centerfire shooting a 150-220 grain bullet. .17 HMR has about 245 ft lbs muzzle energy, the 30-06 about 2,900. .17 is a great target round at 100 meters, and kills prairie dogs. The 30-06 is a great target round at 900 meters, and kills moose, elk, and small armored vehicles.