GST definitions clarify taxable person, supply types, input tax and place of supply under the Arunachal Pradesh GST framework. The Act provides a comprehensive set of definitions for GST administration in Arunachal Pradesh, defining key taxable concepts-such as taxable person, registered person, taxable supply, output tax, input tax and aggregate turnover-and specifying territorial reach, incorporation of related GST enactments, supply classifications (composite, mixed, continuous), transactional roles (supplier, recipient, agent, job worker), and administrative constructs (invoice, return, assessment, audit, Commissioner, ledgers and common portal) that determine liability, jurisdiction and input tax credit entitlement.