Special administrative regions of China in the context of "Province-level divisions of China"

East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of China, Japan, South Korea, and Taiwan are among the world's largest and most prosperous. East Asia borders North Asia to the north, Southeast Asia to the south, South Asia to the southwest, and Central Asia to the west. To its east is the Pacific Ocean.

East Asia, especially Chinese civilization, is regarded as one of the earliest cradles of civilization. Other ancient civilizations in East Asia that still exist as independent countries in the present day include the Japanese, Korean, and Mongolian civilizations. Various other civilizations existed as independent polities in East Asia in the past but have since been absorbed into neighbouring civilizations in the present day, such as Tibet, Manchuria, and Ryukyu (Okinawa), among many others. Taiwan has a relatively young history in the region after the prehistoric era; originally, it was a major site of Austronesian civilisation prior to colonisation by European colonial powers and China from the 17th century onward. For thousands of years, China was the leading civilization in the region, exerting influence on its neighbours. Historically, societies in East Asia have fallen within the Chinese sphere of influence, and East Asian vocabularies and scripts are often derived from Classical Chinese and Chinese script. The Chinese calendar serves as the root from which many other East Asian calendars are derived.

Hong Kong is a special administrative region of China. Situated on China's southern coast just south of Shenzhen, it consists of Hong Kong Island, Kowloon, and the New Territories. With 7.5 million residents in a 1,114-square-kilometre (430 sq mi) territory, Hong Kong is the fourth-most densely populated region in the world.

Hong Kong was established as a colony of the British Empire after the Qing dynasty ceded Hong Kong Island in 1841–1842 as a consequence of losing the First Opium War. The colony expanded to the Kowloon Peninsula in 1860 and was further extended when the United Kingdom obtained a 99-year lease of the New Territories in 1898. Hong Kong was occupied by Japan from 1941 to 1945 during World War II. The territory was handed over from the United Kingdom to China in 1997. Hong Kong maintains separate governing and economic systems from that of mainland China under the principle of one country, two systems.

Macau or Macao is a special administrative region of the People's Republic of China (PRC). With a population of about 710,000 people and a land area of 32.9 km (12.7 sq mi), it is the most densely populated region in the world.

Formerly a Portuguese colony, the territory of Portuguese Macau was first leased to Portugal by the Ming dynasty as a trading post in 1557. Portugal paid an annual rent and administered the territory under Chinese sovereignty until 1887, when Portugal gained perpetual colonial rights with the signing of the Sino-Portuguese Treaty of Peking. The colony remained under Portuguese rule until the 1999 handover to China. Macau is a special administrative region of China, which maintains separate governing and economic systems from those of mainland China under the principle of "one country, two systems". The unique blend of Portuguese and Chinese architecture in the city's historic centre has resulted in its designation as a UNESCO World Heritage Site in 2005.

An open border is a border that enables free movement of people and often of goods between jurisdictions with no restrictions on movement and is lacking a border control. A border may be an open border due to intentional legislation allowing free movement of people across the border (de jure), or a border may be an open border due to a lack of legal controls, a lack of adequate enforcement or adequate supervision of the border (de facto). An example of the former is the Schengen Agreement between most members of the European Economic Area (EFTA and the EU). An example of the latter has been the border between Bangladesh and India, which is becoming controlled. The term "open borders" applies only to the flow of people, not the flow of goods and services, and only to borders between political jurisdictions, not to mere boundaries of privately owned property.

Open borders are the norm for borders between subdivisions within the boundaries of sovereign states, though some countries do maintain internal border controls (for example between the People's Republic of China mainland and the special administrative regions of Hong Kong and Macau, between the United States and the unincorporated territories of Guam, the Northern Mariana Islands and American Samoa, and the Minor Outlying Islands, or between North Korea's provinces and cities). Open borders are also usual between member states of federations, though (very rarely) movement between member states may be controlled in exceptional circumstances. Federations, confederations and similar multi-national unions typically maintain external border controls through a collective border control system, though they sometimes have open borders with other non-member states through special international agreements – such as between Schengen Agreement countries as mentioned above.

The People's Republic of China (PRC) shares land borders with 14 countries (tied with Russia for the most in the world): North Korea, Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, India, Nepal, Bhutan, Myanmar, Laos, and Vietnam, and with two Special administrative regions of China, Hong Kong and Macao. The land borders, counterclockwise from northeast to southwest, are the China–North Korea border, the eastern segment of the China–Russia border, the China–Mongolia border, the western segment of the China–Russia border, the China–Kazakhstan border, the China–Kyrgyzstan border, the China–Tajikistan border, the China–Afghanistan border, the China–Pakistan border, the western segment of the China–India border (the most contested of the Sino-Indian border dispute), the China–Nepal border, the central segment of the China–India border (Sikkim), the China–Bhutan border, the eastern segment of the China–India border, the China–Myanmar border, the China–Laos border, the China–Vietnam border, a 3-kilometre (1.9 mi) internal border with Macau, a Portuguese territory until 1999, and a 30-kilometre (19 mi) internal border with the special administrative region of Hong Kong, which was a British dependency before 1997.

To the west, China has maritime borders with North Korea, Japan and contested limits with Taiwan and other countries in the South China Sea, among other territorial disputes.

The Community of Portuguese Language Countries (Portuguese: Comunidade dos Países de Língua Portuguesa; abbr. : CPLP), also known as the Lusophone Commonwealth or Lusophone Community (Portuguese: Comunidade Lusófona), is an international organization and political association of Lusophone nations across four continents, where Portuguese is an official language. The CPLP operates as a privileged, multilateral forum for the mutual cooperation of the governments, economies, non-governmental organizations, and peoples of the Lusofonia. The CPLP consists of 9 member states and 34 associate observers, located in Africa, América, Asia, Europe and Oceania, totalling 39 countries and 4 organizations.

The CPLP was founded in 1996, in Lisbon, by Angola, Brazil, Cabo Verde, Guinea-Bissau, Mozambique, Portugal, and São Tomé and Príncipe, nearly two decades after the beginning of the decolonization of the Portuguese Empire. Following the independence of East Timor in 2002 and the application by Equatorial Guinea in 2014, both of those countries became members of the CPLP. Galicia (an autonomous community of Spain), Macau (a special administrative region of China), and Uruguay are formally interested in full membership and another 17 countries across the world are formally interested in associate observer status.

"One country, two systems" is a constitutional principle of the People's Republic of China (PRC) describing the governance of the special administrative regions of Hong Kong and Macau.

Deng Xiaoping developed the one country, two systems concept. This constitutional principle was formulated in the early 1980s during negotiations over Hong Kong between China and the United Kingdom. It provided that there would be only one China, but that each region would retain its own economic and administrative system. Under the principle, each of the two regions could continue to have its own governmental system, legal, economic and financial affairs, including trade relations with foreign countries, all of which are independent from those of the mainland. The PRC has also proposed to apply the principle in the unification it aims for with Taiwan.