Pruning shears, hedge shears, and grass clippers are all similar to scissors with two blades coming into contact. They cut through grass, steams, twigs, etc. They are most efficient when sharpened, however it is very important to sharpen them along the factory-cut bevel. It is very important that the tool is sharpened along its angled surface.
For more tips on your outdoor tools check out The Family Handyman - Outdoor Tools