A lot of people get confused on the difference between a tort in a crime. A single act can be both a tort and a crime which is the source of a lot of confusion. But a tort is a civil action where you're trying to gain something financially for what occurred. By comparison a crime is when the community as a whole seeks justice for some wrongdoing. The end result would not be financial but incarceration.
For example, assault can be both a tort and a crime. You can sue the person for your injuries and the community can prosecute them as well.
Negligence is the most common tort. Negligence is simply defined as being careless. Not paying enough attention for the circumstances in which you are surrounded.
Examples of negligence would be automobile accidents caused by speeding or failing to stop at stop signs or signals. It can also be caused by failing to maintain your vehicle. For example, not keeping your brakes in working order would be a case of negligence should you be in an accident that would have been prevented if the brakes worked properly.
The difficulty with negligence is determining whether or not the person was actually negligent. "Due care" is the term used to figure out if someone was doing what they should have been doing to otherwise prevent an accident. Due care is dependent on a number of factors. The circumstances of the situation, the age of the parties, whether anyone had any mental or physical disability and the list goes on. In order to determine if someone was negligent you first have to determine what a reasonable person would've done in the same set of circumstances.
This is where the law becomes very convoluted and the reason why there are so many court cases, is trying to determine what amount of action or lack of action is required in order to determine negligence.