The InChI file format contains the IUPAC International Chemical Identifier, which is a textual identifier for chemical substances designed to provide a standard and human-readable way to encode chemical information and to facilitate the search of such data in databases and on the web. Developed under the auspices of the International Union of Pure and Applied Chemistry (IUPAC), the InChI string represents chemical structures in a layered format, detailing information about connectivity, isotopes, stereochemistry, and electronic charge. Unlike proprietary formats, InChI is non-proprietary and open, allowing chemists and researchers to share chemical data seamlessly across different software platforms and computational chemistry tools without losing structural integrity or facing compatibility issues.