H2

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 H2 informally during the 2002–2004 seasons

Computing

• , level 2 heading markup for HTML Web pages, see HTML element#heading
• H2 Database Engine, a DBMS written in Java
• 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 H2 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

• H2, 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
• The Hardy space H2

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

• *h₂, one of the three laryngeals in the reconstructed Proto-Indo-European language
• 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