When the parties to a dispute are able to focus on their mutual needs and interests and sort the problem out themselves, they can often find a solution that is satisfying to all. You probably negotiate every day without even realizing it. For instance, you and your friends will figure out together how you'll spend the weekend. You can learn negotiation skills. Look for books on the subject, and if it is of interest to you, you can take courses to learn and improve techniques.
Negotiations can take any form that the parties agree to use.
They can be quite informal, such as an open discussion between two people. Some negotiations can be more formal. The parties will hire or use lawyers or other people to help them negotiate. Sometimes the parties might agree that using negotiation will be the first option to settle a dispute. The agreement also might state the form of their negotiations for future disputes.