Every over-the-counter derivative, a swap, a forward, an option traded bilaterally rather than on an exchange, sits on top of a three-layer document stack. The base is the ISDA Master Agreement, a standard-form contract that two parties sign once and then trade under forever. On top sits the Schedule (party-specific elections and amendments) and the Credit Support Annex (CSA), which governs collateral. Each individual trade is captured in a short Confirmation. Crucially, all of these are deemed to form a *single agreement*, which is the legal trick that makes everything else work.