Website localisation is one job with five spellings, and the job is not the translating. Somebody translates: an agency, a machine, a bilingual colleague. What localisation means in practice is deciding which pages exist in which language, getting them served at URLs a search engine can tell apart, and knowing months later which of them are still true. The first is a decision, the second is structure and tags, and the third is a record.
Decide the scope before anything else
Not every page earns a translation. The pages that sell, the pages that answer, and the legal pages a market requires are usually the list; the blog archive usually is not. Sites that skip this decision translate everything, spend four times what they needed to and end up with three hundred stale pages in a language nobody on the team reads.
Structure decides more than the words
Subdirectories, subdomains or country domains, one choice for the whole site, made before the first locale ships. Changing it later is a migration with redirects, and migrations lose rankings. The practical default for most companies is a subdirectory per locale, because it keeps everything on one domain and one set of analytics.
The tags are the part that is invisible when wrong
Every version naming every other version, including itself, with return links that point back. Nothing on the page looks broken when this is wrong; the symptom is the German page ranking in Austria and the English one ranking in Germany, months later, with no error anywhere to explain it.
The record is what nobody keeps
Which page exists in which locale, when it was last translated, and whether the source has changed since. That is a small table and almost no site has it, which is why the answer to whether the French site is current is usually a shrug. It is also the whole of the paid half of this product.
Questions people ask about localization of website
Is localisation different from translation?
Translation is the words. Localisation is the words plus the formats, the structure, the tags and the record of what is current in which language.
Which pages should we localise first?
The ones that sell in that market, plus whatever the market requires legally. The archive can wait, and often should wait forever.
Can we change our URL structure later?
You can, and it is a migration with redirects and a ranking risk. Make the choice once, before the first locale ships.