"Service" or "Service of Process" is making sure the other side gets a copy of the papers you are filing (for example, a complaint). If you are starting a case, your case cannot go forward until the other side is served. Someone who is capable of serving must physically give a copy of all necessary forms to the person whom you filed a complaint against in court.
It is very important that you do this correctly. If you do not, then the court may dismiss your case. If you have an uncontested case and the other side is willing, there is a special rule to make service easier.
The court will issue a Writ of Summons, 5 to 10 days after you file your Complaint, Petition, or Motion. The Clerk of the Court will send the Writ of Summons to your mail address, as the person who has filed. Attach the original copy of the summons to one copy of all of the forms that you filed with the court (Complaint, Domestic Case Information Report, Financial Statement, etc.). You must make sure that the Writ of Summons is attached to a copy of the complaint, petition, or motion. These papers must be served on the other side.
HAGUE SERVICE CONVENTION TREATY OBLIGATION TO REFRAIN FROM SERVICE BY MAIL: American courts have held that formal objections to service by mail made by countries party to a multilateral treaty or convention on service of process at the time of accession or subsequently in accordance with the treaty are honored as a treaty obligation, and litigants should refrain from using such a method of service.
Service of Process overboard can enjoin upon you to get the authorization from court. Before sending of email to me, I recommend that you should consult an attorney in your state.