EM explained

EM, Em or em may refer to:

Arts and entertainment

EM, the E major musical scale
Em, the E minor musical scale
Electronic music, music that employs electronic musical instruments and electronic music technology in its production
Encyclopedia Metallum, an online metal music database
Eminem, American rapper

Em (restaurant), a restaurant in Mexico City
Aero Benin (IATA code), a defunct airline
Empire Airlines (IATA code), a charter and cargo airline based in Idaho, US
Erasmus Mundus, an international student-exchange program
Estado de Minas, a Brazilian newspaper
European Movement, an international lobbying association
ExxonMobil, a large oil company formed from the merger of Exxon and Mobil in 1999
La République En Marche! (sometimes shortened to "En Marche!"), a major French political party

Emergency management, a discipline that studies dealing with and avoiding risks
Energy management, planning and operation of energy production and energy consumption units
Environmental management, the management of the interaction of human societies with the environment

Effective microorganisms, a series of products intended to improve soil quality and plant growth
Extracellular matrix, the connective tissue supporting cells in multicellular organisms
Membrane potential (E_m), of a cell

Emergency medicine, a medical specialty dealing with acute illnesses and injuries that require immediate attention
Erythema multiforme, a skin condition that usually follows an antecedent infection or drug exposure
Erythromelalgia, a disorder that typically affects the skin of the feet and/or hands, causing redness, heat and pain
Extensive metabolizer, a term used in pharmacogenomics to refer to individuals with normal metabolic activity

Exametre or exameter (Em), an SI unit of length equal to 10¹⁸ metres
Electromagnetic spectrum, the range of all possible frequencies of electromagnetic radiation
Electromigration, the transport of conducting solid material caused by electric current through it
Electromagnetism, one of the fundamental physical forces
Electromechanics, combines electrical engineering and mechanical engineering

Nikon EM, an SLR camera made by the Nikon Corporation in the late 1970s
Electron microscope, a type of microscope that uses electrons to "illuminate" a specimen and create an enlarged image
Electron multiplier, a vacuum-tube structure that multiplies incident charges by means of secondary emission
Electronic monitoring, a form of surveillance used in criminal justice
Atlantic Equatorial mode, a climate pattern of the Atlantic Ocean
Expectation–maximization algorithm, an algorithm for finding maximum likelihood estimates of parameters in probabilistic models

Electrician's mate, an occupational rating in the U.S. Navy and U.S. Coast Guard
David Em (born 1952), an American computer art pioneer
EM gauge, a scale used in model railways
Etymologicum Magnum, in the bibliography of the largest Byzantine lexicon