There are great differences between the tasks of ombudsmen as well as between the emphases in their work. However, a common feature of the institution everywhere is that the ombudsman defends people and their legal rights against possible mistakes on the part of the authorities.

Another common feature is that ombudsmen are independent authorities chosen by legislators. They have broad powers to conduct investigations and receive information. In addition, they act flexibly and it is an easy and simple matter for citizens to contact them and have their cases examined.

The ombudsman institution is often closely identified with a single figure who has a prominent public profile. In other countries, such as Sweden, there are several ombudsmen, who divide tasks between them.

Ombudsmen do not generally have power to order authorities to act in any particular way. The means at their disposal have more to do with mediation and conciliation, making proposals, guidance and issuing reprimands. Only in very few countries, such as Finland and Sweden, do the ombudsmen have the power to bring prosecutions.

The different emphases that can be observed within ombudsman institutions are reflected also in the titles used. If the aspect of defending human rights is emphasised, the title can be, for example, Human Rights' Commissioner or Defensor del Pueblo. If the emphasis is on mediation and conciliation between citizens and administration, the ombudsman has the French title Médiateur. When the principal consideration is oversight of legality and good governance, this task is reflected in the name Ombudsman, signifying the institution's Swedish origin and name.