Choose a gas model if your property is on the large side or has tall grass and weeds. Electric string trimmers are best for smaller yards and more modest needs. Of these, cordless models are limited to short trimming times between battery charges.
Even a blue-ribbon lawn won’t win any landscaping prizes if it has shaggy, untrimmed walkways and tall grass poking up around trees and fence posts. Modern string trimmers address a garden variety of lawn-grooming concerns with better performance and convenience for less money.