Place of Supply and Taxable Person definitions determine GST applicability and registration obligations under the state law. The Act provides a comprehensive glossary of terms that govern state GST scope, liability and compliance, defining core concepts such as taxable person, registered person, taxable supply, input tax and aggregate turnover, sets out the legal tests for types of supplies (composite, mixed, continuous), and fixes place, location and registration criteria that determine intra State and inter State applicability.