Samsung 85″ Class 4K Crystal UHD (2160p) LED Smart TV with HDR UN85AU8000 2021

2021 (MMXXI) was a common year starting on Friday of the Gregorian calendar, the 2021st year of the Common Era (CE) and Anno Domini (AD) designations, the 21st year of the 3rd millennium and the 21st century, and the 2nd year of the 2020s decade.

Like the year 2020, 2021 was also heavily defined by the COVID-19 pandemic, due to the emergence of multiple COVID-19 variants. The major global rollout of COVID-19 vaccines, which began at the end of 2020, continued in 2021. Most major events scheduled for 2020 that were postponed due to the pandemic were hosted in 2021, including the 26th United Nations Climate Change Conference, Expo 2020, and sporting events such as UEFA Euro 2020, the 2020 Summer Olympics and Paralympics, as well as the 2021 Copa América.

2021 additionally witnessed numerous advancements in space exploration, particularly by the United Arab Emirates, NASA and SpaceX, including the launch of the James Webb Space Telescope.

Civil unrest grew in 2021, with coups occurring in Sudan, Myanmar, Mali and Guinea, and insurrections occurring in Armenia and the United States.

4K, 4-K or 4k may refer to:

• 4000 (number)
• Four kibibytes (4 × 1024 bytes, better written 4 KiB)
  • 4K disk sector size (Advanced Format)
  • 4K demoscene compo, a computer art competition using programs limited to 4 kibibytes
  • The Java 4K Game Programming Contest
• 4K resolution, a collective term for digital video formats having a horizontal resolution of approximately 4,000 pixels
  • 4K UHDTV, an ultra-high-definition television format
• 4K, the IATA airline code for Askari Aviation
• 4K, an alternative name for Cuatro Cabezas (Four Heads), an Argentine multimedia production company.
• 4K, model of Toyota K engine
• 4K, the production code for the 1976 Doctor Who serial The Brain of Morbius
• 4KScore test for prostate cancer screening
• Kenn Borek Air, a Canadian airline IATA code

85 may refer to:

• 85 (number)
• one of the years 85 BC, AD 85, 1885, 1985, 2085
• 85 Io, a main-belt asteroid

A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.

The word crystal derives from the Ancient Greek word κρύσταλλος (krustallos), meaning both "ice" and "rock crystal", from κρύος (kruos), "icy cold, frost".

Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third category of solids is amorphous solids, where the atoms have no periodic structure whatsoever. Examples of amorphous solids include glass, wax, and many plastics.

Despite the name, lead crystal, crystal glass, and related products are not crystals, but rather types of glass, i.e. amorphous solids.

Crystals, or crystalline solids, are often used in pseudoscientific practices such as crystal therapy, and, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements.

Samsung Group (Korean: 삼성; Hanja: 三星; RR: samseong [samsʌŋ]; stylised as SΛMSUNG) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Digital City, Suwon, South Korea. It comprises numerous affiliated businesses, most of them united under the Samsung brand, and is the largest South Korean chaebol (business conglomerate). As of 2024, Samsung has the world's fifth-highest brand value.

Samsung was founded by Lee Byung-chul in 1938 as a trading company. Over the next three decades, the group diversified into areas including food processing, textiles, insurance, securities, and retail. Samsung entered the electronics industry in the late 1960s and the construction and shipbuilding industries in the mid-1970s; these areas would drive its subsequent growth. Following Lee's death in 1987, Samsung was separated into five business groups – Samsung Group, Shinsegae Group, CJ Group, Hansol Group, and JoongAng Group.

Samsung industrial affiliates include Samsung Electronics, Samsung Heavy Industries, Samsung Engineering and Samsung C&T Corporation. Other subsidiaries include Samsung Life Insurance and Cheil Worldwide. Notable Samsung industrial affiliates include Samsung Electronics (the world's largest information technology company, consumer electronics maker and chipmaker measured by 2017 revenues), Samsung Heavy Industries (the world's second largest shipbuilder measured by 2010 revenues), and Samsung Engineering and Samsung C&T Corporation (respectively the world's 13th and 36th largest construction companies). Other notable subsidiaries include Samsung Life Insurance (the world's 14th largest life insurance company), Samsung Everland (operator of Everland Resort, the oldest theme park in South Korea) and Cheil Worldwide (the world's 15th largest advertising agency, as measured by 2012 revenues).

Smart may refer to a high level of intelligence or "street smarts".

"Smart" or SMART may also refer to the following.

With or WITH may refer to:

• With, a preposition in English
• Carl Johannes With (1877–1923), Danish doctor and arachnologist
• With (character), a character in D. N. Angel
• With (novel), a novel by Donald Harrington
• With (album), a 2014 album by TVXQ
• With (EP), a 2021 EP by Nam Woo-hyun