hreflang
An annotation declaring alternate language or regional versions of a page, so search engines serve the appropriate one to each user.
InternationalMulti-language SEO
Multilingual SEO
Optimising a site that serves several languages, ensuring each version is fully indexable, correctly annotated and not mixed within a single page.
In full
Google's guidance is to use different URLs per language rather than switching by cookie or script, to avoid side-by-side translations on one page, and to let users change language without automatic redirection. Navigation, metadata, structured data and error pages must be translated too, not just body copy. Machine-translated content is not automatically a policy violation, but unreviewed translations at scale risk being judged unhelpful.
Example
A site serving nine languages uses `/es/`, `/it/`, `/pl/` paths with fully translated navigation, metadata and hreflang sets.
Related terms
Transcreation
Recreating content for another market so it works culturally and commercially, rather than translating it word for word.
International SEO
Structuring and optimising a site so the right language and country version is served to the right audience in each market's search results.
Multilingual sitemaps
XML sitemaps carrying `xhtml:link rel="alternate" hreflang` annotations, an alternative to placing hreflang in page head markup.
Internationalised domain name
A domain name containing non-ASCII characters, encoded for DNS as ASCII Punycode beginning with `xn--`.