Negligence means the failure to exercise due care to prevent an accident that could happen. So if you're a property owner, it means you have to remove the snow or ice from your property. If there's a broken step, you have to correct it. If you're driving a motor vehicle, you have to look. You have to avoid accidents. You have to follow the rules of the road. So the failure to exercise due care, reasonable care, is what is considered negligence.
Violation of a statute, or a law, an ordinance, also can be evidence of negligence as well. So if you violate a speeding restriction, that can be evidence of negligence. If you make a turn when you're not supposed to, you turn left when there's oncoming vehicles, that's negligence. Failure to exercise reasonable care.