Purpose: The reason for which something exists or is done, made, used.
Responsible: answerable or accountable, as for something within one's power, control, or management
Responsibility: the state or fact of being responsible
Ability: competence in an activity or occupation because of one's skill, training, or other qualification
Responsible: answerable or accountable, as for something within one's power, control, or management
Responsibility: the state or fact of being responsible
Ability: competence in an activity or occupation because of one's skill, training, or other qualification