There are a number of different theories and hypotheses regarding early state formation that seek generalizations to explain why the state developed in some places but not others. Other scholars believe that generalizations are unhelpful and that each case of early state formation should be treated on its own.

Voluntary contend groups theories of people came together to form states as a result of some shared rational interest.

Conflict theories of state formation regard conflict and dominance of some population over another population as key to the formation of states.

The first states of sorts were those of early dynastic Sumer and early dynastic Egypt, which arose from the Uruk period and Predynastic Egypt respectively around approximately 3000 BCE.

Although state-forms existed before the rise of the Ancient Greek empire, the Greeks were the first people known to have explicitly formulated a political philosophy of the state, and to have rationally analyzed political institutions. Prior to this, states were described and justified in terms of religious myths.

Several important political innovations of classical antiquity came from the Greek city-states (polis) and the Roman Republic. The Greek city-states before the 4th century granted citizenship rights to their free population; in Athens these rights were combined with a directly democratic form of government that was to have a long afterlife in political thought and history.

Political globalization began in the 20th century through intergovernmental organizations and supranational unions. The League of Nations was founded after World War I, and after World War II it was replaced by the United Nations. Various international treaties have been signed through it. Regional integration has been pursued by the African Union, ASEAN, the European Union, and Mercosur. International political institutions on the international level include the International Criminal Court, the International Monetary Fund, and the World Trade Organization.

The history of the world is commonly understood as the history of humanity spanning the major geopolitical developments of about five millennia, from the first civilizations to the present. In terms such as world religion, world language, world government, and world war, the term world suggests an international or intercontinental scope without necessarily implying participation of every part of the world.

The world population is the sum of all human populations at any time; similarly, the world economy is the sum of the economies of all societies or countries, especially in the context of globalization:

• Terms such as «world championship», «gross world product», and «world flags» imply the sum or combination of all sovereign states.
• While the Germanic word thus reflects a mythological notion of a domain of Man compare Midgard.
• The corresponding word in Latin is mundus literally «clean, elegant» as an act of establishing order out of chaos.

Itself a loan translation of Greek cosmos «orderly arrangement.» presumably as opposed to the divine sphere on the one hand and the chthonic sphere of the underworld on the other, the Greco-Latin term expresses a notion of creation.

«World» distinguishes the entire planet or population from any particular country or region: world affairs pertain not just to one place but to the whole world, and world history is a field of history that examines events from a global (rather than a national or a regional) perspective. Earth, on the other hand, refers to the planet as a physical entity, and distinguishes it from other planets and physical objects.

Was also classically used to mean the material universe, or the cosmos: «The worlde is an apte frame of heauen and earthe, and all other natural thinges contained in them.»

The term can also be used attributively, to mean «global», or «relating to the whole world», forming usages such as world community or world canonical texts.

By extension, a world may refer to any planet or heavenly body, especially when it is thought of as inhabited, especially in the context of science fiction or futurology.

In philosophy, the term world has several possible meanings. In some contexts, it refers to everything that makes up reality or the physical universe. In others, it can mean have a specific ontological sense. While clarifying the concept of world has arguably always been among the basic tasks of Western philosophy, this theme appears to have been raised explicitly only at the start of the twentieth century and has been the subject of continuous debate. The question of what the world is has by no means been settled.

The traditional interpretation of Parmenides work is that he argued that the everyday perception of reality of the physical world is mistaken, and that the reality of the world is One Being: an unchanging, ungenerated, indestructible whole.