In the world of push lawnmowers, newer isn't always better. The modern, gas-powered lawnmower is often preferred because of its greater convenience, but the older, manual push mowers often give better results overall. Choosing the right lawnmower requires you to evaluate the benefits and drawbacks of the different types and decide which fits your needs best.
Reel mowers are the simplest type of push lawnmowers. A real mower has a series of blades on a reel, which rotate around in a circle past a flat blade called the bed knife. As the reels pass the knife, they compress blades of grass between the two edges and cut through them like scissors. Reel mowers are almost silent, simple, inexpensive, environmentally friendly and require very little maintenance. They are also good for the grass, since they cut it instead of tearing it like other types of mowers. On the downside, they require more work than other push mowers, since the reel is turned by the operator pushing the mower and not by a motor. They also are fairly slow and cannot cut the grass to different heights.
Rotary mowers use a single vertically mounted engine that spins a blade beneath the protective deck. The blade slices the grass as it spins, trimming it as the operator pushes the mower along. The deck prevents debris from shooting out from the high-speed blade and causing injury. These mowers usually either propels grass clippings out to the side or the back, or slice them several times and leave them sitting on the lawn as a fine mulch, which helps distribute nutrients back into the grass. Rotary mowers can be either powered by gas, an electric cord or electric batteries. Although rotary mowers do not provide quite as even a cut as reel mowers, they require less work, can usually be adjusted to different heights and get the job done quickly.
Self-propelled mowers are rotary mowers with a built-in drive system. Rotary mower are heavy, which can make them somewhat difficult push on hilly terrain. The drive system allows the lawnmower operator to walk behind the mower at a comfortable speed without having to push it as hard. Self-propelled mowers usually have several speeds or a continuously variable drive which matches the walking speed of the operator.