It is likely a problem with the carburetor if a lawn edger won't start. It may have clogs which are preventing the spark at the plug.
did you check and make sure you have plenty of oil. or maybe your lawn mower just needs a break.
make sure the gas valve is turned on and you put the air filter in right
replace it
replace battery & starter solenoid.. possibly carb.
get a new one
Monster House
vovlo wont start using key
Flywheel key (or shear pin) can shear off which will put the motor out of time and wont start . It could do damage to some other parts but that is the most common.
no spark, no gas getting to cylinder, dirty carb, dirty fuel filter, wrong fuel/air mix on carb to name a few, dirty air filter....
check the distributor
do you have gas in the tank
Try pulling out the spark plug and clearing the cylinder