Acronym in the context of Firewall (physics)

The Popular Front for the Liberation of Saguia el-Hamra and Río de Oro, better known by its acronym Polisario Front, is a Sahrawi nationalist liberation movement seeking to end the occupation of Western Sahara through the means of self-determination and armed resistance.

Tracing its origin to a Sahrawi nationalist organization known as the Movement for the Liberation of Saguia el Hamra and Wadi el Dhahab, the Polisario Front was formally constituted in 1973 with the intention of launching an armed struggle against the Spanish occupation which lasted until 1975, when the Spanish decided to allow Mauritania and Morocco to partition and occupy the territory. The Polisario Front proclaimed the Sahrawi Arab Democratic Republic (SADR) on 27 February 1976, and waged a war to drive out the two armies. It forced Mauritania to relinquish its claim over Western Sahara in 1979 and continued its military campaign against Morocco until the 1991 ceasefire, pending the holding of a UN-backed referendum which has been consistently postponed ever since. In 2020 the Polisario Front declared the ceasefire over and resumed the armed conflict.

BRICS is an intergovernmental organization comprising ten countries: Brazil, China, Egypt, Ethiopia, India, Indonesia, Iran, Russia, South Africa and the United Arab Emirates. Its conceptual origins were articulated by Russian foreign minister Yevgeny Primakov in 1998, and can be traced to informal forums and dialogue groups such as RIC (Russia, India, and China) and IBSA (India, Brazil, and South Africa). BRIC was originally a term coined by British economist Jim O'Neill, and later championed by his employer Goldman Sachs in 2001, to designate a group of emerging markets.

The bloc's inaugural summit was held in 2009 and featured the founding countries of Brazil, Russia, India, and China; they adopted the acronym BRIC and formed an informal diplomatic club where their governments could meet annually at formal summits and coordinate multilateral policies. South Africa joined the organization in September 2010, which was then renamed BRICS, and attended the third summit in 2011 as a full member. Iran, Egypt, Ethiopia, and the United Arab Emirates attended their first summit as member states in 2024 in Russia. Indonesia officially joined in early 2025, becoming the first Southeast Asian member. The acronym BRICS+ or BRICS Plus has been informally used to reflect new membership since 2024.

Radar is a system that uses radio waves to determine the distance (ranging), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations and terrain. The term RADAR was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term radar has since entered English and other languages as an anacronym, a common noun, losing all capitalization.

A radar system consists of a transmitter producing electromagnetic waves in the radio or microwave domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. This device was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution.

Scuba diving is an underwater diving mode where divers use breathing equipment completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The word scuba is an acronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their source of breathing gas, affording them greater independence and movement than surface-supplied divers, and more time underwater than freedivers. Although compressed air is commonly used, other gas blends are also employed.

Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open-circuit, making longer dives feasible. Rebreathers extend the time spent underwater compared to open-circuit for the same metabolic gas consumption. They produce fewer bubbles and less noise than open-circuit scuba, which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media diver to avoid bubble interference.

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow and the optical amplifier patented by Gordon Gould.

A laser differs from other sources of light in that it emits light that is coherent. Spatial coherence allows a laser to be focused to a tight spot, enabling uses such as optical communication, laser cutting, and lithography. It also allows a laser beam to stay narrow over great distances (collimation), used in laser pointers, lidar, and free-space optical communication. Lasers can also have high temporal coherence, which permits them to emit light with a very narrow frequency spectrum. Temporal coherence can also be used to produce ultrashort pulses of light with a broad spectrum but durations measured in attoseconds.

A contraction is a shortened version of the spoken and written forms of a word, syllable, or word group, created by omission of internal letters and sounds.

In linguistic analysis, contractions should not be confused with crasis, abbreviations and initialisms (including acronyms), with which they share some semantic and phonetic functions, though all three are connoted by the term "abbreviation" in layman’s terms. Contraction is also distinguished from morphological clipping, where beginnings and endings are omitted.

WASH (or WatSan, WaSH; stemming from the first letters of "water, sanitation and hygiene") is a sector in development cooperation, or within local governments, that provides water, sanitation, and hygiene services to communities. The main purposes of providing access to WASH services are to achieve public health gains, implement the human right to water and sanitation, reduce the burden of collecting drinking water for women, and improve education and health outcomes at schools and healthcare facilities. Access to WASH services is an important component of water security. Universal, affordable, and sustainable access to WASH is a key issue within international development, and is the focus of the first two targets of Sustainable Development Goal 6 (SDG 6). Targets 6.1 and 6.2 aim for equitable and accessible water and sanitation for all. In 2017, it was estimated that 2.3 billion people live without basic sanitation facilities, and 844 million people live without access to safe and clean drinking water. The acronym WASH is used widely by non-governmental organizations and aid agencies in developing countries.

The WASH-attributable burden of disease and injuries has been studied in depth. Typical diseases and conditions associated with a lack of WASH include diarrhea, malnutrition, and stunting, in addition to neglected tropical diseases. There are additional health risks for women, for example, during pregnancy and birth, or in connection with menstrual hygiene management. Chronic diarrhea can have long-term negative effects on children in terms of both physical and cognitive development. Still, collecting precise scientific evidence regarding health outcomes that result from improved access to WASH is difficult due to a range of complicating factors. Scholars suggest a need for longer-term studies of technological efficiency, greater analysis of sanitation interventions, and studies of the combined effects of multiple interventions to better analyze WASH health outcomes.

The chief of staff of the Air Force (acronym: CSAF, or AF/CC) is the service chief of the United States Air Force. They are the principal military advisor to the secretary of the Air Force on matter pertaining to the Air Force. They are a member of the Joint Chiefs of Staff, and thereby a military adviser to the National Security Council, the secretary of defense, and the president. The chief of staff is typically the highest-ranking officer on active duty in the Air Force, unless the chairman and/or the vice chairman of the Joint Chiefs of Staff are Air Force officers.

The chief of staff of the Air Force is an administrative position based in the Pentagon. The chief of staff does not have operational command authority over Air Force forces. That is within the purview of the combatant commanders who report to the secretary of defense. The chief of staff exercises supervision of Air Force units and organizations as the designee of the secretary of the Air Force.

The general counsel of the Department of the Air Force (acronym SAF/GC) is the chief legal officer of the U.S. Department of the Air Force.

By U.S. law, the general counsel of the Department of the Air Force is appointed from civilian life by the president of the United States upon the advice and consent of the United States Senate, and performs such duties as the secretary of the air force specifies.

The term Latin America and the Caribbean (LAC) is an English-language acronym referring to the Latin American and the Caribbean region. The term LAC covers an extensive region, extending from The Bahamas and Mexico to Argentina and Chile. The region has over 670,230,000 people as of 2016, and spanned for 21,951,000 square kilometres (8,475,000 sq mi).

BASE jumping (/beɪs/) is the recreational sport of jumping from fixed objects, using a parachute to descend to the ground. BASE is an acronym that stands for four categories of fixed objects from which one can jump: buildings, antennas (referring to radio masts), spans (bridges) and earth (cliffs). Participants jump from a fixed object such as a cliff and after an optional freefall delay deploy a parachute to slow their descent and land. A popular form of BASE jumping is wingsuit BASE jumping.

In contrast to other forms of parachuting, such as skydiving from airplanes, BASE jumps are performed from fixed objects that are generally at much lower altitudes, and BASE jumpers only carry one parachute.BASE jumping is significantly more hazardous than other forms of parachuting and is widely considered to be one of the most dangerous extreme sports.

Obazoa is a proposed sister clade of Amoebozoa (which together form Amorphea). The term Obazoa is based on the OBA acronym for Opisthokonta, Breviatea, and Apusomonadidae, the group's three constituent clades.

Determining the placement of Breviatea and Apusomonadida and their properties is of interest for the development of the opisthokonts in which the main lineages of animals and fungi emerged. The relationships among opisthokonts, breviates and apusomonads are not conclusively resolved (as of 2018), though Breviatea is usually inferred to be the most basal of the three lineages.

An abbreviation (from Latin brevis 'short') is a shortened form of a word or phrase, by any method including shortening, contraction, initialism (which includes acronym), or crasis. An abbreviation may be a shortened form of a word, usually ended with a trailing period. For example, the term etc. is the usual abbreviation for the Latin phrase et cetera.

A QAPF diagram is a doubled-triangle plot diagram used to classify igneous rocks based on their mineralogy. The acronym QAPF stands for "quartz, alkali feldspar, plagioclase, feldspathoid (foid)", which are the four mineral groups used for classification in a QAPF diagram. The percentages (ratios) of the Q, A, P and F groups are normalized, i.e., recalculated so that their sum is 100%.

Shimon bar Yochai (Zoharic Aramaic: שמעון בר יוחאי, Šimʿon bar Yoḥay) or Shimon ben Yochai (Mishnaic Hebrew: שמעון בן יוחאי), also known by the acronym Rashbi, was a 2nd-century tanna or sage of the period of Roman Judaea and early Syria Palaestina. He was one of the most eminent disciples of Rabbi Akiva. The Zohar, a 13th-century foundational work of Kabbalah, is ascribed to him by Kabbalistic tradition, but this claim is universally rejected by modern scholars.

In addition, the essential legal works called the Sifre and Mekhilta of Rabbi Shimon ben Yochai are attributed to him (not to be confused with the Mekhilta of Rabbi Ishmael, of which much of the text is the same). In the Mishnah, where he is the fourth-most mentioned sage, he is referred to as simply "Rabbi Shimon" except in Hagigah 1:7. In baraitas, midrash, and gemara, his name occurs either as Shimon or as Shimon ben Yochai. An 8th-century pseudonymous attribution of divine revelations to Shimon by the angel Metatron is also known, called The Secrets of Rabbi Simon ben Yohai.