when a party or his /her lawyer demands his/her right against other party it is called NOTICE.Some time notices are precondition for filing a cause becauseof law and some time they are optional.
BUT when NOTICE does not get complied by party upon whom it was served,a petition or suit,or application is moved in court,whereup on court with intention to afford hearing to other side of the case issue an in information sheet in a prform proforma called SUMMONS fixing a date for REPLY of petion,plaint,or application moved before it.
If summons has been sent to opposite party(O.P.) has been returned with endorsement of post man that addressee was not found on the address,the petioer has to pray the cort to serve the O.P.via alternative mode such as by publication in news paper and after order of court petioner has to take steps,say deposit fees of the newspaper,when newspaper is published it provides a copy to the court and withdraws the fees deposited in court,then if on published date the O.P.does not turnup,the cort may record his absence and can order that case will proceed here now exparty and can prononce an exparty judgement and order agaist O.P.