A more thorough explanation:

Service is the formal delivery of legal documents to inform someone that they are being sued. This is also known as service of process. Proper service is required before someone can be brought to court.

In federal court, a plaintiff initiates a lawsuit by serving a defendant a summons with a copy of the complaint. Other legal documents must also be served on every party involved in the case. Service can be established through personal service, leaving it at the person’s office or usual place of abode, service by mail, leaving it with the court clerk if the person has no known address, filing it with the court’s electronic filing system, or by serving the person through any means to which they consented.

For example, if someone is suing a government agency, they must properly serve the agency within a certain time period. If they fail to do so, their case may be dismissed. In Systems Signs Supplies v. U.S. Dept. of Justice, the plaintiff did not properly serve the U.S. Department of Justice within the required time period, and their case was dismissed.

Proper service is important because it ensures that everyone involved in the case has been notified and has the opportunity to respond. This is a requirement for due process under the Fifth Amendment of the Constitution.