ARI may refer to:

• ARI, Chacalluta International Airport in Arica, Chile (IATA code)
• Aberdeen Royal Infirmary, a tertiary referral hospital in Aberdeen, Scotland
• Acoustics Research Institute of the Austrian Academy of Sciences
• Acute respiratory infection
• Added Reality Interface, a fictional piece of technology in the video game Heavy Rain
• Alternative for a Republic of Equals, now known as Civic Coalition ARI, a political party in Argentina
• Alternative Routing-ID Interpretation, an extension to the PCI Express computer input/output standard that supports the virtual machine computing model
• American Refrigerant Institute, a trade association in North America
• Arthur Rylah Institute for Environmental Research, an organization conducting environmental research in Victoria, Australia
• Artist-run initiatives 
• Associazione Radioamatori Italiani, an amateur radio organization in Italy
• Astronomisches Rechen-Institut, an institute based in Heidelberg, Germany
• Astrophysics Research Institute at Liverpool John Moores University, England
• Autism Research Institute, an autism-related organization
• Autofahrer-Rundfunk-Informationssystem, a system formerly used in Germany to indicate traffic announcements on FM radio broadcasts
• Automated Readability Index, a readability algorithm
• Avicenna Research Institute, an Iranian biotechnology research institute
• Ayn Rand Institute, an organization devoted to exposition of Ayn Rand's philosophy, Objectivism
• ARI by Ariana Grande, Ariana Grande's debut fragrance

Ari may refer to:

• Ari (name), a name in various languages, including a list of people and fictional characters
• Rabbi Isaac Luria (1534–1572), Jewish rabbinical scholar and mystic known also as Ari

A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image scanner, or motion picture film scanner. Raw files are named so because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent colorspace. There are dozens, if not hundreds, of raw formats in use by different models of digital equipment (like cameras or film scanners).