Plain English Meaning
ARINC is the organization that sets the common rules for how navigation information is written into the databases used by aircraft avionics. Because of these rules, navigation data from any approved provider can be loaded into any compatible flight management system and read correctly.
Full Definition
A company, originally formed by U.S. airlines in 1929, that develops and publishes industry standards for aviation electronics, data formats, and communications. Its specifications — most notably ARINC 424 — define the standardized format used to encode navigation data (waypoints, airways, procedures, approaches) in airborne navigation databases worldwide.