A waiver of liability is a legal document that a person who participates in an activity signs to acknowledge the risks involved in his or her participation in that activity and, by doing so, absolves the business or person providing that activity from legal liability.
A release is a contractual agreement by which one individual assents to relinquish a claim or right under the law to another individual against whom such claim or right is enforceable. The right or claim given up in a release usually involves contracts or torts. A general release deals with all possible claims that are in existence or may arise between the parties, whereas a specific release is generally limited to specific and clearly describes claims.