The contemporary notion of rights is universalist and egalitarian. Equal rights are granted to all people. By contrast, most historical notions of rights were authoritarian and hierarchical, with different people being granted different rights, and some having more rights than others. For instance, the rights of a father to be respected by his son did not indicate a duty upon the father to return that respect, and the divine right of kings to hold absolute power over their subjects did not leave room for many rights to be granted to the subjects themselves. Conversely, modern conceptions of rights often emphasize liberty as among the most important of rights, though conceptions of liberty (e.g. positive vs negative) frequently differ.
There are numerous different theoretical distinctions in accordance with which rights may be classified.
Rights may be considered to be either of a purely moral or ethical character, as in the idea of natural rights, which holds that we obtain certain rights from nature that cannot be legitimately modified by any legislative authority; or they may be considered to be of an artificial, man-made character, as in the idea of legal rights, which are arbitrary human constructs, created by legislative authority and always subject to change.
Another distinction may be drawn between claim rights and liberty rights. A liberty right grants permission, whereas a claim right grants an entitlement. As entitlements, claim rights serve as rules of interaction between people, as they entail constraints and obligations upon the actions of other individuals or groups (e.g. if a person has a right to life, others cannot have the liberty to kill that person). As permissions, liberty rights are also known simply as liberties, but are still frequently referred to as rights (e.g. "I have a right to do x" often means "I am permitted to do x"), though some deny that such usage is proper.
A further distinction may be drawn between negative and positive rights, where the former require inaction on the part of others and the latter require action on the part of others (in the sense of rights as claims or entitlements), or where the former permits inaction and the latter permits action (in the sense of rights as liberties or permissions).
Furthermore, rights may be divided into individual rights, which are held by individual people, and group rights, which are held by an ensemble of people or a subgroup of people who have a certain characteristic in common. In some cases there can be tension between individual and group rights. In other cases, the view of rights held by one group can come into sharp and bitter conflict with the view of rights held by another group. For instance, compare Manifest destiny with Trail of Tears.
Other distinctions between rights draw more on historical association or family resemblance than on such precise philosophical distinctions. These include the distinction between civil and political rights and economic, social and cultural rights, between which the articles of the Universal Declaration of Human Rights are often divided. Another conception of rights groups them into three generations. These distinctions have much overlap with that between negative and positive rights, as well as between individual rights and group rights, but these groupings are not entirely coextensive.
The specific enumeration of rights accorded to people has historically differed greatly from one century to the next, and from one regime to the next, but nowadays is normally addressed by the constitutions of the respective nations (in the case of legal rights) or a particular philosophical theory (in the case of natural rights).
Rights about particular issues, or the rights of particular groups, are often areas of special concern.
Particular groups whose rights are of particular concern includes animals, and amongst humans particular groups such as children (see both children's rights and youth rights for two different angles), mothers, fathers, and men and women in general.