This is the system in international world, this type of person is known as 'DIPLOMATIC REPRESENTATIVE' or 'DIPLOMATIC AGENT'. special importance is given to such person in international law .Such type of person have many immunities and privileges. And having some duties which are understand by brief explanation as following as under-
CLASSIFICATION OF DILOMATIC AGENT-The diplomatic agent have been classified according to their status and functions, it was again dropped by 1961 convention on Diplomatic relations. THUS, at present, the classification of diplomatic envoys is as follows-
1)-AMBASSADORE AND LEGATES- Ambassador and legates are the diplomatic agents of first category. they are the representatives of the completely sovereign states. They are either appointed as ambassador or permanent representative appointed by pope are called legates.
2)-MINISTERS PLENI-POTENTIARY AND ENVOYS EXTRAORDINARY-Minister plenipotentiary and envoys extraordinary are the diplomatic agents of secured category and as compared to the diplomatic-agents of the first category, they enjoy less privilege and immunity.
3)-CHARGE-D-AFFAIRES-Charge-d-affaires are the  diplomatic agents of the last category. The main reason for this is that they are not appointed by the head of the state. they are appointed  by the foreign ministers of states. in right and status they are considered below the minister resident.
It was made clear in Article-14(2) of the Vienna convention on diplomatic relation that apart from precedent and etiquette, there is hardly any difference between the diplomatic agents of above mentioned categories. Obviously, there is no difference so for as their privilege and immunity are concerned.
-IMMUNITIES AND PRIVILEGES OF DIPLOMATIC AGENTS-Several immunities and privileges have been given to diplomatic agent under international law. S.S.DHAWAN has considered these immunities and privileges a main  base of international law.
These immunities and privileges are as follows-
1)- INVIOLABILITY- In international law, diplomatic agents have been given sufficient personal security. This immunity is recognised under Vienna convention 1961. In Article 29 0f the said convention it has been said that "Diplomatic agents will enjoy physical inviolability. He will not be liable to any form of arrest or detention. Honourable treatment will be given to him by taking or keeping state and every efforts shall be made to maintain his freedom and reputation as intact."
But  if the behaviour and conduct of diplomatic agent is found to be objectionable and if charge is imposed upon him of interference in internal affairs of keeping state, then he may be declared as PERSONA NON GRATA  and may be asked to leave the country (Article- 9 and 43 of Vienna convention 1961), Indian diplomatic agent in Pakistan RAJESH MITTAL was tortured by officers of intelligence agency of Pakistan on 25th may 1992 and with the result, India declared two Pakistani diplomatic agents in India as PERSONA NON GRATA and was asked to leave India is an good example of this.
2)-IMMUNITY FROM CIVIL ADMINISTRATIVE JURISDICTION-It is well established principle of international law that the diplomatic agents enjoy immune from civil and administrative jurisdiction.
Under this immunity:-
1)- no suit can be filed against diplomatic agent for recovery of debt;
2)- he can not be arrested in action for debt recovery;
3)- his property can not be ceased and sold.
3)-IMMUNITY FROM CRIMINAL JURISDICTION -Diplomatic agents have also been given immunity from criminal jurisdiction. Under Article 31 of Vienna convention 1961, it has been provided that "diplomatic agents shall be immune from the criminal jurisdiction of the state". It means that the keeping state shall not prosecute and penalise any diplomatic agent  under any circumstance. Even he can not be arrested. But it does not mean that he can behave as he likes in keeping state.  It is his duty that he should obey all rules and laws of keeping state and should not do such act which is inconsistent with the internal system of keeping state. If any misconduct is done by him, the keeping state may suspend him and ask him to leave the country.
For example- in 1995 the first secretary sultan Mahmood DEHADER in AFGAN  embassy was suspended by government of India in Delhi in consequence of criminal charge and misconduct and was sent back to AFGANISTAN . This immunity is not available to children and relatives of diplomatic agents who are not residing with them.
4)-IMMUNITY REGARDING RESIDENCE-There is inviolability of residence of diplomatic agent. Entry in house and even his house can not be searched. if there is any person hidden in his house to whom the police wants to arrest, normally the diplomatic agent surrenders such person to the police.
5)-IMMUNITY FROM GIVING EVIDENCE IN THE COURT-Diplomatic agent is immured from presenting himself for giving evidence in the courts. He can not be made bound for giving evidence in the court. In Article-31(2) of Vienna convention, it has been said "NO DIPLOMATICE AGENT WILL BE MADE BOUND FOR GIVING EVIDENCES IN A COURT AS WITNESS". But if any diplomatic agent wants to give evidence at his own then he will be allowed to present himself in a court for giving evidence.
6)-IMMUNITY FROM PAYMENT OF TAXES-In international law, diplomatic agent are immune from payment of taxes and customs duties. According to Article 34 and 36 of Vienna convention "A DIPLOMATIC AGENT SHALL BE IMMUNE FROM PAYMENT OF ALL TYPES OF TAXES AND DUTIES". But if any diplomatic agent wants to pay taxes in exchange for enjoyment of facilities of water and electricity he will be allowed to pay. But if does not pay any tax , no legal action will be taken against him.
7)- IMMUNITY FROM POLICE RULES AND REGULATIONS-Diplomatic agent are immune from police rules and regulations. If he obeys these rules: it will be treated as his good manners towards the state for maintenance of good relations.
8)-RIGHT OF WORSHIP AND DEVOTION TO GOD- Diplomatic agent have right to worship according to his own consciousness is his embassy. But he does not enjoy the right to preach his own religion and to make the citizens of keeping states bound to participate in his worship and devolution.
9)-IMMUNITY FROM LOCAL AND MILITARY OBLIGATIONS- According to Article-35 of Vienna convention 1961,the diplomatic agent have been immune from local and military obligations.
10)-RIGHT TO EXERCIESE CONTROL AND JURISDICTION OVER THEIR OFFICERS AND FAMILIES.
11)-FREEDOM OF COMMUNICATION FOR OFFICIAL PURPOSE-This freedom has been conferred upon by Article-27 of Vienna convention on the diplomatic relations, 1961. This Article provides that they have freedom to communicate with their home-state in connection with their functions and duties.
12)-RIGHT TO TRAVEL FREELY IN TERRITORY OF THE RECEIVING STATE- This new right has, for the time, been introduced in Article-26 of the Vienna convention on Diplomatic relations,1961. Article 26 provides that diplomatic agents can travel in the territory of the receiving state subject, of course, to the condition that they cannot go to the prohibited places or the places which are important from the point of view of the security of the receiving state.
13)-IMMUNITY FROM SOCIAL SECURITY PROVISIONS-According to Article 33, a diplomatic agent shall with respect to services rendered for the sending state be exempt from social security provisions which may be in force in the receiving state.
14)-IMMUNITY FROM INSPECTION OF PERSONAL BAGGAGE-Article 36(2) of Vienna convention 1961 provides that the personal baggage of a diplomatic agent be exempt from inspection.
SOURCES OF THIS ARTICLE-
⦁ INTERNATIONAL LAW AND HUMAN RIGHTS (BOOK) BY S.K. KAPOOR 17th EDITION.
WRITTEN BY - MITALI SONI, B.A.L.LB. 7th SEM. MLSU, UDAIPUR.