What is the difference between duties and responsibilities?

Duties are ascribed to people naturally, this is expected of and from a reasonable human beings i.e. duty of care, but responsibilities are demanded-duties that are brought upon ourself because of our close connections with others e.g. responsibilties you have towards your children.

The difference between this two terminology can be describe in a very simple words...

1) Duty : -

To do the work assigned is our duty.

2) Responsibility - To complete the work assigned accurately, efficiently and within the given deadlines is responsibility.

Examples : -

1) A watchman has to sit on the gate  of the premises is his duty.

2) A watchman has to ensure the security and the safety of the premises is his responsibility.

If i have to answer in one line it would be like this.

Duties you perform and responsibility you undertake.