A gas-powered lawn mower offers several benefits over an electric one. For example, the increased power allows them to easily cut through longer/tougher grass, and they are not limited by cord length or how long the battery lasts.
Cordless tools/machines are suited to a variety of different situations, as you are not limited to only working in places with power sources nearby.
The mower can discharge the cut grass to the side. The cut grass helps to fertilise the lawn and helps preserve moisture in the summer, and means that you do not have to empty a grass bag/box. However, this is not as effective as a mulching lawn mower.
A self-propelled lawn mower requires less effort from the user, as you don’t have to manually push it forward.
A rotary mower cuts the grass with a blade or disc that rotates on a vertical axis. They have the benefit of requiring little maintenance, and are often cheaper and more lightweight than, for example, a cylinder lawn mower.
A steel deck’s main advantage is that it is durable, and if you hit a stone it will only make a dent rather than fracturing.