What is i18n (Internationalization)?
Internationalization, abbreviated i18n because there are eighteen letters between the i and the n, is the practice of building software so it can adapt to different languages and regions without engineering rework. It covers externalizing user-facing strings into translation files, handling Unicode text correctly, formatting dates and numbers per locale, and designing layouts that survive longer text or right-to-left scripts.
The key distinction: i18n is the engineering work, localization (l10n) is the content work. You internationalize once so you can localize many times. If strings are hardcoded in templates or concatenated in PHP, no amount of translation effort will produce a correct French or Japanese version. The code has to be ready first.
In Laravel, i18n mostly means wrapping strings in __() or trans(), keeping translations in lang/ files (PHP arrays or JSON), and setting the active locale per request. Once that structure exists, adding a new language is a content task, not a code task.
{{-- Blade: externalized string, ready for any locale --}}
<h1>{{ __('dashboard.welcome', ['name' => $user->name]) }}</h1>
// lang/en/dashboard.php
return [
'welcome' => 'Welcome back, :name',
];