Vatican City is an example of an enclave because it is an independent state that is completely surrounded by the borders of another state, in this case, Italy. Switzerland, although landlocked, is bordered by many countries and is thus not technically an “enclave.”

The Philippines is considered a fragmented state because its territory is physically divided, by the ocean, into several distinct regions that make it harder for a centralized government to wield control. Although the territories of the United Kingdom and the United States are not wholly contiguous they are not usually considered to be fragmented states because the vast majority of their significant territory is contiguous.

A compact state is a state that is reasonably small and centralized; it usually somewhat resembles a square. Compact states are usually easier for a centralized government to manage because every outlying region in the country is roughly equidistant from the center. Poland is the classic example of a compact state. The opposite of a compact state is an elongated state.

The term “annexation” is used to describe the internationally legal addition of new territory into an existing state. When we use the phrase “internationally legal” this is of course a dubious distinction, but essentially a nation can “annex” more territory in certain situations without it being considered an act of war. The United States, during its history of westward expansion, consistently annexed new territory, primarily because the Native Americans were not considered legitimate claimants to the land by the international community.

A unitary state, as opposed to a federal state like the United States, is a state where laws are administered uniformly by one central government. There are no regional authorities, like the various states in the United States, who compete for power and dilute the authority of the central government.

Federalism is a system of government where power is shared (in various arrangements) between a centralized government and various regional authorities. The United States is a federal country because power is shared between the national government and the governments of the various states.

Apartheid was an official government policy of South Africa for much of the twentieth century. It was based on the belief that there is an inherent difference between the races and that people of different ethnicities should be prevented from working and living together by rules and regulations.

Apartheid was a social policy enforced by the South African government for much of the twentieth century, between its independence and the end of apartheid in 1990. It was a policy designed to enforce racial segregation—to keep black people and white people from interacting in daily life.

The "nation-state" refers to the modern notion of a sovereign nation, wherein a unified ethnic and linguistic group, a "nation," is essentially synonymous with a unified political power, a "state." The 1648 Peace of Westphalia, which ended the lengthy wars of religion in Western Europe and redrew political boundaries, is one of the key moments in establishing nation-states in a modern viewpoint. From that point forward, nationalism took on  the nation-state as a primary goal and motivating force.

A homogenous nation-state is a country with a population that is ethnically, racially, or religiously homogenous. 98% of Japan's population is ethnically Japanese, while the other countries listed are all multi-cultural states.