# Glossary > The domain and API terms used in this documentation, in English and German. The German column gives the term used on the German pages of this documentation. Code, field names and operation ids are the same in both languages. ## Products and passports | Term | German | Meaning | | ----------------- | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Battery passport | Batteriepass | The digital record of one individual battery under Regulation (EU) 2023/1542 (Art. 77). In BatteryPass every unit has one passport with numbered, signed versions. See [Passports](https://passport.kabin.sh/docs/en/concepts/passports). | | Passport version | Passversion | One publication of a passport. It never changes and holds the snapshot, the public document and their signatures. | | Economic operator | Wirtschaftsakteur | The manufacturer, importer or authorised representative that places a battery on the market and is responsible for its passport. | | Battery model | Batteriemodell | The commercial product with name, SKU, GTIN and category. See [Battery models](https://passport.kabin.sh/docs/en/concepts/battery-models). | | Model version | Modellversion | One technical state of a battery model, valid from its `effective_from` date. Model-level values are stored here. Status `draft`, `approved` or `superseded`. | | Unit | Einheit | One physical battery with a serial number, assigned to a model version. Called `Battery` in the API. | | GTIN | GTIN | Global Trade Item Number, the GS1 number of the battery model. BatteryPass stores it with 14 digits. | | GS1 Digital Link | GS1 Digital Link | A web address built from GS1 identifiers, here `/01/{gtin}/21/{serial}`. It is what the QR code carries. See [GS1 Digital Link](https://passport.kabin.sh/docs/en/concepts/digital-link). | | Resolver | Resolver | The service behind the Digital Link: it sends browsers to the public page and machines to the public JSON or a linkset. | | Second life | Second Life | A battery that is repurposed, reused or remanufactured. It becomes a new unit with its own passport that links to the original. | ## Data and review | Term | German | Meaning | | ------------------- | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Field registry | Feldregister | The versioned list of all passport fields: level, tier, requirement per battery category, validation and export paths. Read it with [`getRegistrySchema`](https://passport.kabin.sh/docs/en/api-reference/registry/get-registry-schema). | | Tier (access tier) | Zugriffsstufe | Who may see a field or document: `public`, `legitimate_interest`, `authority` or `internal`. See [Access tiers](https://passport.kabin.sh/docs/en/concepts/access-tiers). | | Provenance | Herkunft | Where a value comes from: source, author, time, reviewer and evidence, kept for every revision. See [Provenance and review](https://passport.kabin.sh/docs/en/concepts/provenance-and-review). | | Evidence | Nachweis | A document that supports a value, such as a declaration of conformity or a test report. Evidence is versioned and has its own tier. | | Four-eyes principle | Vier-Augen-Prinzip | The rule that a value is approved by a different member than the one who recorded it. On by default for every organisation. | ## Condition and lifecycle | Term | German | Meaning | | --------------- | ----------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Condition data | Zustandsdaten | Measured values of one unit, the registry's `condition` section. Accepted as measurements, without a review step. See [Condition data and lifecycle](https://passport.kabin.sh/docs/en/concepts/condition-and-lifecycle). | | State of health | Gesundheitszustand (State of Health, SoH) | How much of its original capability a battery still has. The registry expresses it through fields such as capacity fade, remaining capacity and, for EV batteries, the state of certified energy. | | Lifecycle event | Lebenszyklus-Ereignis | A dated record of something that happened to a unit, such as a repair or an inspection. Events change no data of the unit. | ## API | Term | German | Meaning | | ----------------- | ------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | API key | API-Schlüssel | An organisation's credential `bp_live_…`, sent as `Authorization: Bearer`. It acts with a viewer's rights. See [Authentication](https://passport.kabin.sh/docs/en/authentication). | | Scope | Scope | What a key may do: `read` (read data), `condition` (report condition data and lifecycle events) or `import` (stage spreadsheet imports that members commit). | | Problem Details | Problem Details | The error format of RFC 9457 (`application/problem+json`), here with a stable `code` and a `request_id`. See [Errors](https://passport.kabin.sh/docs/en/errors). | | Keyset pagination | Keyset-Paginierung | Paging with `limit` and an opaque `cursor`; a page returns `items` and `next_cursor`, which is `null` on the last page. See [Pagination](https://passport.kabin.sh/docs/en/pagination). | ## Signatures | Term | German | Meaning | | ------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | JCS | JCS | JSON Canonicalization Scheme (RFC 8785): one fixed way to serialise JSON, so the same data always gives the same bytes to hash and sign. | | Ed25519 | Ed25519 | The signature algorithm BatteryPass uses (EdDSA on Curve25519, RFC 8032). Public keys have 32 bytes, signatures 64 bytes. | | JWK | JWK | JSON Web Key (RFC 7517), a public key as JSON. BatteryPass publishes its Ed25519 keys as `OKP` keys (RFC 8037) in a JWK set at `/.well-known/batterypass/keys.json`. See [Signatures](https://passport.kabin.sh/docs/en/concepts/signatures). |