Dear friend,
Resignation is the unilateral initiative of the employee to foreclose his contract of employment with his employer.
First, to make it formal it should be conveyed in writing to the employer through the proper channel, if any.
Second, the effective date of resignation should be prospective giving sufficient notice time to the employer as prescribed in the contract of employment. Even in the absence of such notice period, it should be submitted sufficiently in advance so as to enable the employer to consider it for acceptance.
Third, the resignation takes effect only from the date of relieving after formal acceptance by the employer.
Thus resignation is a process involving the initiative of the exiting employee and the follow up action of the employer subject to the fulfilment of the exit clause of the contract of employment.
Till the completion of all these formalities by both the employer and the employee, the contract of employment continues.