Annex

An annex is something that is attached to or accompanies a main thing, and the term is used in several senses. In architecture, an annex is a subsidiary building or a long extension connected to a larger structure. It is designed to provide additional space—such as offices, classrooms, laboratories, or storage—while remaining functionally part of the same complex. Annexes may be freestanding but linked by corridors or passages, and they are distinct from the original building only by size or purpose.

In political and legal contexts, annexation refers to the act of incorporating a territory into an existing state, country, or political entity. This can occur through agreement, purchase, or force, and it has implications for sovereignty, law, and governance. Annexation is often controversial and subject to international law and recognition by other states.

In documents, an annex (also called an annexure or appendix in some jurisdictions) is supplementary material attached to the end of a report, treaty, or contract. An annex may include maps, schedules, technical specifications, data, or legal clauses. While annex and appendix are sometimes used interchangeably, their precise meaning and placement can vary by country and document type.

Examples can be found in contract law, urban planning, and international agreements, where annexes help organize complex information without overloading the main text.