The word register can have several meanings.  Very often it means: something that is written down so that there is a record (written proof) of something.  It may, for example be a list of names. 

It can also be used as a verb: to register, i.e. to write something down in an official register (e.g. a special book), e.g. to register a birth, marriage or death.  

Registration is the act of registering or being registered.

Documents, records and government
 Aircraft registration, compulsory registration of an aircraft with a government authority
 Check register, booklet used to record account transactions
 Family register, a registry used in many countries to track information of a genealogical or legal interest
 Regesta, a record of assets in ancient Rome, from which the English word register is derived
 Registered mail, trackable mail service available in most countries
 Registered nurse
 Registered partnership, similar to a civil union
 Registered trademark symbol
 Registration statement, in the United States, a set of documents including a prospectus, that a company must file with the Securities and Exchange Commission before it proceeds with an initial public offering
 Summit register (or canister), record of visitors to a mountain's summit
 Vehicle registration, compulsory registration of a vehicle with a government authority
 Vehicle registration plate,  metal or plastic plate attached to a motor vehicle or trailer for official identification purposes
 Voter registration, entry onto an electoral roll

Technology and telecommunication
 Cash register, a device for recording retail transactions and storing money
 FCC registration program, relating to telephone equipment in the United States
 Hardware register, a placeholder for information about some hardware condition
 Image registration, process of transforming different sets of data into one coordinate system
 Printing registration, in color printing, the correlating of colors in a single image
 Processor register, a component inside a central processing unit for storing information
 Quantum register, the quantum mechanical analogue of a classical processor register
 Register, an air-return vent or heating air duct in home and office heating.
 Register (photography), attribute of a lens mount system
 Register (sculpture), the separation of multiple pictographic scenes from each other
 Register signaling, in telecommunications
 Registered user, one who registers for a program or website and provides his or her credentials to access it
 Status register, a collection of flag bits for a micro-processor

Linguistics
 Register and contour tones, a linguistics term for tones distinguished by relative pitch
 Register (phonology), a language that combines tone with phonation
 Register (sociolinguistics), a form of a language used for a particular purpose or social setting

Publications
 The Des Moines Register, Des Moines, Iowa newspaper
 Federal Register, public journal of the United States federal government
 New Haven Register, New Haven, Connecticut newspaper
 The Orange County Register, Santa Ana, California, newspaper
 The Register, genealogical journal and the official publication of the New England Historic Genealogical Society
 The Register (originally South Australian Gazette and Colonial Register), first newspaper in South Australia
 The Register, technology news website
 Sheffield Register, a defunct Sheffield, England, newspaper

Maritime
 Indian Register of Shipping
 International Register of Shipping
 Korean Register of Shipping
 Lloyd's Register
 Naval Vessel Register
 Norwegian International Ship Register
 Norwegian Ship Register
 Polish Register of Shipping
 Russian Maritime Register of Shipping
 USS Register, the name of more than one United States Navy ship

Music
 Register (music), the relative "height" or range of a note, melody, part, musical instrument, etc.
 Registration (organ), the art of combining the different sounds of a pipe organ to make the right sound for the piece of music

Comics
 Registration acts (comics), fictional legislation that is a focus in Marvel Comics

Places
 Register, Georgia, United States

Related pages
 Incorporation (business)—includes registration of a corporation
 Licensure
 Registry (disambiguation)
 Registrar