This article establishes the core terminology for the UAE Corporate Tax Law. It defines over 50 key terms, including 'Business', 'Taxable Person', 'Free Zone Person', 'Qualifying Income', and 'Permanent Establishment'. These definitions are foundational for interpreting the scope and application of the entire Decree-Law, ensuring consistent understanding of obligations and exemptions. Crucially, as amended by FDL 60/2023, it introduces the terms 'Top-up Tax' and 'Multinational Enterprise', laying the groundwork for implementing the OECD's Pillar Two global minimum tax rules within the UAE's domestic legal framework, ensuring clarity for subsequent articles.