A more thorough explanation:

In legal terms, a party refers to a person or group that is involved in a legal transaction or lawsuit. This can include:

• A person who has a direct interest in an agreement or contract
• A plaintiff or petitioner who brings a case to court
• A defendant or respondent who is defending against a case

For example, if two people are signing a contract, they are both parties to the agreement. If one person sues another for damages, the person bringing the lawsuit is the plaintiff and the person being sued is the defendant.

A "third party" is someone who is not directly involved in the transaction or lawsuit, but may be affected by it. For instance, if two people are signing a contract and a third person will be impacted by the terms of the agreement, they are a third party.

Understanding who the parties are in a legal situation is important for determining rights and responsibilities, as well as for resolving disputes.