# Glossary of terms

> Every term this documentation uses - XLIFF, translation unit, project, voice profile, tier, cache hit, flagged unit - defined in one place.

> Canonical HTML: https://aixlifftranslate.com/docs/glossary-of-terms/
> Last updated: 2026-09-08

Definitions for the vocabulary used across these pages and in the app.

## Content and file formats

**XLIFF**
: XML Localisation Interchange File Format - the standard exchange format for translation work.
  WPML exports it, and it is what you upload here. The version WPML produces is XLIFF 1.2, and
  that is the version this tool is built and tested against.

**Translation unit**
: One translatable piece of a file: a paragraph, a heading, a meta description, a structured
  data block. WPML decides the boundaries; we do not re-cut them. A unit is the thing that gets
  translated, counted and billed.

**Source and target**
: The source is your original text. The target is the translation. In a fresh WPML export every
  target is empty; filling them in is the job.

**Page**
: The billing unit in pricing. Pages are a normalised measure of volume, which is why a very
  long page and a very short one do not cost the same.

## Organising your work

**Project**
: One website. It owns that site's voice profile, its protected terms, and its translation
  cache. Translations are never shared between projects, because two projects are two different
  sites with two different voices.

**Job (or batch)**
: One upload, processed as a unit. A job contains files, files contain units. Job status,
  progress and cost are all reported at this level.

**Voice profile**
: The brand-voice instructions applied to every unit in a project - identity, tone, per-language
  guidance, and rules for body content and metadata. See [Brand voice](/docs/voice-profiles/).

**Glossary term (protected term)**
: A word or phrase that must survive translation unchanged - typically a brand or product name.
  Declared to the model before translation and verified afterwards.

## How text is handled

**Content type**
: The strategy a unit is routed to: body content, metadata, structured data, or not
  translatable. It determines the instructions, the constraints and the checks applied. See
  [How it works](/docs/how-it-works/).

**Structured data (JSON-LD)**
: Machine-readable markup describing your business, products or FAQs for search engines. Parsed
  as JSON so only human-readable fields are translated; identifiers, URLs, dates and type names
  are left exactly as they are.

**Placeholder**
: A template token such as `%%title%%` or `%%sitename%%` that WordPress or an SEO plugin
  replaces at render time. Never translated, and checked for after translation - a lost
  placeholder produces a visibly broken page.

**Shortcode**
: A WordPress `[bracketed]` tag. Preserved exactly, in the same quantity, in the same order.

## Cost and quality

**Duplicate**
: A unit whose source text is identical to another unit's in the same upload. Translated once
  and applied to all of them.

**Cache hit**
: A unit answered from a previously stored translation instead of being translated again.
  Requires the same source text, target language and content type, within the same project. See
  [Why the second run costs less](/docs/caching-and-dedup/).

**Fresh translations**
: An option that ignores stored translations on read while still storing the new results. Used
  when you want a genuinely new answer - after a significant voice change, for example.

**Tier**
: The quality level chosen for a job - **Medium** or **Pro**. Medium is the sensible default for
  body content at volume; Pro costs more per page and is worth it for copy that carries weight.
  You choose a tier rather than a specific model, so improvements reach you without you having
  to track which engine is behind it.

**Flagged unit**
: A unit that failed its post-translation checks, or that fell back to its source text. Flagged
  so it surfaces in review rather than shipping unnoticed. A flag means "look at this", not
  "this is broken".

**Review**
: Reading translations against their sources, editing what needs editing, and marking units as
  checked. Review state is per unit and is kept with the job.

## Round trip

**Import (into WPML)**
: Loading finished XLIFF back into WordPress through WPML's Translation Management screen. This
  is when your site actually changes - nothing before it touches your database.

**Reverse import**
: Loading *already translated* XLIFF into this tool - translations done elsewhere, or by a human
  - so they become reviewable and reusable here. It performs no translation and costs nothing.