Glossary | Obscura Trace

Term	Definition
Analysis (analyse)	Reading of one or more sources in five phases: file traversal, metadata, hashing, image analysis, similarity index. Modifies no file.
Catalog (catalogue)	Local database of Obscura Trace (`catalog.sqlite`). Contains everything except your photos.
Companion (compagnon, sidecar)	File that accompanies a main file, such as an XMP next to a RAW. Always travels with it.
Established / estimated confidence (confiance établie / estimée)	Established: a verified fact (identical SHA-256). Estimated: an inference, always marked “estimé” (estimated).
Copy-first	Principle whereby a move is first a verified copy; the source is removed only afterward.
Trash (Corbeille)	macOS Trash of the disk concerned. Default destination of the sources of a move and of replaced files. Never emptied by the app.
Exact duplicate (doublon exact)	Files with strictly identical content, established by full SHA-256.
Probable duplicates (doublons probables)	The only name, on every screen, for very similar images that the analysis matches by their visual fingerprints (dHash and pHash within 10 bits). An inference, never a fact: each group carries its “estimée” (estimated) confidence and awaits your confirmation in the Centre de revue (Review Center). Neither cropping nor rotation is recognized. Distinct from exact duplicates, established by SHA-256.
Dry run (simulation)	Plan computed for reading, which cannot be executed.
Fingerprint (SHA-256) (empreinte)	Digital signature of a file’s content: two files with the same fingerprint have the same content.
Visual fingerprint (dHash, pHash) (empreinte visuelle)	Signature of an image’s appearance, which withstands recompression and resizing.
Freed space (espace libéré)	Bytes actually permanently deleted by transfers.
Recoverable space (espace récupérable)	Space taken up by extra copies or by sources in the Trash; nothing has been freed yet.
Group (groupe)	Set of files that the analysis matches together (exact duplicates or probable duplicates).
Job	Long-running task tracked by the app: analysis, plan, transfer, renaming. Each job has an identifier and a state.
Transaction journal (journal de transactions)	Register in which each operation on a file is written before it is performed, then its result. Basis of any resume.
Manifest (manifeste)	`manifest.json` file written in the destination, describing each transferred file, its origin and its fingerprint.
Master	Copy to keep first in a group; recommended by the app, chosen by you.
`.obscura-part`	Temporary name of a copy in progress, before verification. Never an original.
Plan	Exact list of operations a transfer will perform, computed before any write.
Resume (reprise)	Continuation of an interrupted transfer, from the journal, without copying again what is verified.
Authorization bookmark (signet d’autorisation)	Durable reference to a folder you designated, which makes it possible to find it again without designating it again.
Source	Disk or folder designated for analysis. One per disk.
Collision strategy (stratégie de collision)	What happens when a file with the same name exists at the destination: Comparer (Compare, the default), Ignorer (Skip), Renommer (Rename), Remplacer (Replace).
Volume	Disk or partition.
Weak volume (volume faible)	Volume whose file system does not guarantee a reliable file identifier (exFAT, FAT, unknown format).