title: H2
text: # H2
  
  H2, H02, or H-2 may refer to:
  
  ## Arts and media
  
  * Armenia 2 (H2), a private television company broadcasting in Armenia and Nagorno-Karabakh
  * H2 (A&E Networks), the rebranded name of the former channel History International
     * H2 (American TV channel), the American version of the channel
  * H2 (manga), a baseball manga by Mitsuru Adachi
  * Halo 2, a video game for the Xbox, created and developed by Bungie
  * Halloween II (2009 film), initially abbreviated to H2
  * Hollywood Squares, referred to as $H^2$ informally during the 2002–2004 seasons
  
  ## Computing
  
  * <h2></h2>, level 2 heading markup for HTML Web pages, see HTML element#heading
  * H2 (database), an open-source Java SQL database-management system
  * DSC-H2, a 2006 Sony Cyber-shot H series camera
  * HTTP/2, major revision of HTTP, often abbreviated in discussions as h2, and identifying itself to other servers as h2 in TLS negotiation or h2c in the HTTP Upgrade header
  * LGA 1155 CPU socket, also known as Socket H2
  
  ## Roads and transportation
  
  * Interstate H-2, a highway in Hawaii, located on the island of Oahu
  * London Buses route H2
  
  ## Science and mathematics
  
  ### Biology and medicine
  
  * ATC code H02 Corticosteroids for systemic use, a subgroup of the Anatomical Therapeutic Chemical Classification System
  * British NVC community H2, a heath community in the British National Vegetation Classification system
  * Histamine $H_2$ receptor
  * Prostaglandin H2
  * H-2, the Major histocompatibility complex of the mouse (equivalent of the Human Leukocyte Antigens)
  * $H^{2}$ or $h^{2}$, wide- or narrow-sense heritability
  
  ### Chemistry
  
  * $H_2,$ the chemical formula for hydrogen gas (dihydrogen)
  * Deuterium (Hydrogen-2, H-2, $^2H),$ the isotope of hydrogen with one proton, one neutron, and one electron
  
  ### Other uses in science and mathematics
  
  * H II region, a region of interstellar atomic hydrogen that is ionized
  * *h₂, one of the three laryngeals in the reconstructed Proto-Indo-European language
  * The Hardy space $H^2$
  
  ## Vehicles
  
  ### Air and space
  
  * H-II, a family of Japanese liquid-fueled rockets
     * H-IIA
     * H-IIB
     * H-II Transfer Vehicle, a Japan Aerospace Exploration Agency uncrewed spacecraft
  * H-2 MUPSOW, a precision-guided glide bomb manufactured by Pakistan
  * Landgraf H-2, an American single-seat twin-rotor helicopter produced in 1944
  * Standard H-2, a U.S. Army reconnaissance plane produced in 1916
  
  ### Automobiles
  
  * Haval H2, a Chinese subcompact SUV
  * Hummer H2, an American full-size SUV
  
  ### Motorcycles
  
  * Kawasaki H2 Mach IV, 1970s two-stroke motorcycle
  * Kawasaki Ninja H2, 2010s supercharged motorcycle
  
  ### Rail
  
  * LB&SCR H2 class, a British LB&SCR locomotive
  * GNR Class H2, a class of British steam locomotives
  * LNER Class H2, a class of British steam locomotives
  * H02 locomotive (Germany), a high-pressure steam locomotive made in 1930
  * Saxon XII H2, a German steam locomotive produced in 1922
  * PRR H2, a model within the American PRR locomotive classification
  * H2, designation for METRORail Siemens S70 light rail vehicles
  
  ### Sea
  
  * HMAS Success (H02), a Royal Australian Navy Admiralty S-class destroyer completed in 1918
  * HMS Exmouth (H02), a British Royal Navy E-class destroyer commissioned in 1934
  * HMS H2, a British Royal Navy H class submarine commissioned in 1915
  * USS H-2 (SS-29), a U.S. Navy H-class submarine commissioned in 1913
  
  ## Other uses
  
  * H-2 Air Base, a military air base in Iraq
  * H2 (classification), a para-cycling classification
  * H-2A Visa, a United States visa for temporary or seasonal agricultural work
  * H2, the second half of the business year
  * H2 lamp, a halogen vehicle headlamp no longer manufactured
  * H2, a model of hurricane tie manufactured by Simpson Strong-Tie Co.
  * Sky Airline (IATA code H2)
  * Area H2, an Israeli-controlled area under the Hebron Protocol
  * H2 as the nickname for New Zealand civil servant Heather Simpson
  