Petrol or Electricity?
If you have a small lawn that can be cut by a petrol or electric mower, the choice is a personal one. Electric mowers are quieter than petrol ones and are more environmentally friendly. The need to have electric mowers serviced is less important and the prices are generally cheaper.
Petrol mowers are generally more powerful and are free from trailing cables which can get caught up in garden obstacles. Larger lawns generally need the extra power afforded by petrol mowers and electric mowers are limited by the length of cables.
An alternative that achieves the freedom from cables but retains electrical benefits is the rechargeable battery mower. A battery powered mower is ideal for the smaller lawn that can be cut in about half an hour. Battery powered mowers are only available as hand propelled.