> ## Documentation Index > Fetch the complete documentation index at: https://docs.moduluslabs.io/llms.txt > Use this file to discover all available pages before exploring further. # Glossary > Payments and Modulus terms, with Philippine local context ## Overview Plain definitions of the terms used across the Modulus APIs. New to payments or new to the Philippine market? Start here. ## Money and amounts Two amount conventions are in use. Check each API's reference before you send a value. | Term | Meaning | | -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Minor units (Ecom) | Payment Links and Payment Intents take amounts as **integers in the currency's smallest unit**, no decimals. For PHP that is centavos: `150000` means PHP 1,500.00. | | Major units (QR, Terminal) | The QR and Terminal Gateway APIs take amounts as a **decimal in the main unit**: `500.00` means PHP 500.00. | | Centavo | 1/100 of a Philippine peso. | | ISO 4217 | The currency-code standard. `PHP` is the Philippine peso. | ## Keys and access | Term | Meaning | | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `sk_` (secret key) | Server-side key. Creates resources (payment links, payment intents). Never expose it in a browser or mobile app. Newer keys are prefixed `sk_test_` (sandbox) or `sk_live_` (production). | | `pk_` (publishable key) | Browser key used by the JavaScript SDK to confirm a payment, scoped to a single intent by its `client_secret`. Safe to ship in your frontend. Prefixed `pk_test_` or `pk_live_`. | | Entity hierarchy | Organization levels a key can be scoped to: **partner** (all merchants and branches under it), **merchant** (all branches under it), **branch** (one branch only). Access is restricted to the key's level. | | `merchant_branch_reference_number` | Identifies the branch a resource belongs to. Required for partner- and merchant-scoped keys; branch-scoped keys can omit it. | ## Ecom concepts | Term | Meaning | | ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Payment link | A shareable hosted checkout URL. Create it server-side, send your customer the `url`, and Modulus hosts the checkout page. See [Payment Links](/docs/ecom/payment-links). | | Payment intent | An amount a customer has agreed to pay, created server-side and confirmed in the browser by the JavaScript SDK. See [JavaScript SDK](/docs/ecom/jssdk/introduction). | | `id` vs `client_secret` | The intent `id` is the public identifier (safe in logs, webhooks, dashboards). The `client_secret` is the capability that authorizes confirming that one intent. They are separate on purpose: a value that is widely logged should not also authorize a charge. | | `order_reference` | Your own identifier stored on the payment, used to reconcile a payment back to your records. | | `idempotency-key` | A client-generated id that lets you safely retry a create request without creating a duplicate. See [Authentication](/docs/ecom/authentication#idempotency). | | `administrative_area` | The state or province in a billing address, `{ code, name }` with a short ISO 3166-2 subdivision code (for example `{ "code": "CA", "name": "California" }`). Only required for US, CA, and CN billing addresses; for PH it is not required and is dropped. | ## Cards and 3D Secure | Term | Meaning | | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | 3D Secure (3DS) | An issuer authentication step (an OTP or biometric prompt) that helps confirm the cardholder is genuine. | | Challenge | A 3DS flow where the customer must complete a step, such as entering an OTP. | | Frictionless | A 3DS flow the issuer approves with no customer interaction. | | ECI | Electronic Commerce Indicator. A value returned by 3DS that indicates the authentication outcome and who carries liability for a disputed payment. | | PAN | Primary Account Number, the card number itself. With the JavaScript SDK the PAN is entered into Modulus-hosted fields and never touches your page. | ## Encryption (QR and Webhooks) | Term | Meaning | | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Encryption Key | A separate key (from your Secret Key) used to encrypt and decrypt JWE payloads in the QR and Webhooks APIs. The Secret Key authenticates requests; the Encryption Key wraps and unwraps payloads. | | JWE | JSON Web Encryption. QR and Webhooks carry payloads as a compact JWE inside a `{ "Token": "" }` envelope (`alg` `A256KW`, `enc` `A256CBC-HS512`). | | Activation code | Identifies one of your sub-merchant accounts. Sent as the `Activation-Code` header on webhook deliveries so you know which account an event belongs to. | | `merchantReferenceNumber` | The reference you set when creating a QR. It is echoed in the webhook payload - correlate a payment to your order on this, not on `referenceNumber`. | | `webhookAction` | The single event a webhook fires on: `QRPH_SUCCESS` or `QRPH_DECLINED`. Deduplicate deliveries on `(transactionId, webhookAction)`. | ## Terminals and onboarding | Term | Meaning | | ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `deviceId` vs `connectionId` | On the Terminal Gateway, `deviceId` is a stable identifier that survives reconnects; `connectionId` is the transient per-connection id. Always address terminals by `deviceId`. | | Activation code (terminal) | The physical device identifier used to filter terminal transactions in Transaction Reporting. | | `onboardingReferenceNumber` | The id returned when a merchant onboarding application is submitted. Poll `/v2/onboard/{ref}/status` with it for the approval result. | ## Reconciliation | Term | Meaning | | ------------------- | ------------------------------------------------------------------------------------ | | `transaction_id` | Modulus reference for a completed payment. | | `approval_code` | The issuer's authorization code for an approved payment. | | `reconciliation_id` | Settlement / reconciliation reference used to match a payment to a settlement batch. | | `invoice_number` | Modulus invoice number for a payment. |