If you are a site collection administrator, you are provided with two types of features to help you support users who speak different languages.
Multiple Language User Interface (MUI). Use the MUI feature to create sites in different languages than the default language for your SharePoint installation. To set up this feature, see Make multiple languages available for your site's user interface. Or to let individual users change the display language for their site’s personal user interfaces, see Change your language and region settings.
Variations (Enhanced translation workflow and machine translation services). Use the variations feature to create a source publishing website and then make copies of its content that can be translated into different languages. (The variations feature only works with publishing sites.)
Beginning September 2018 the Machine Translation Services are being deprecated in SharePoint Online. The Machine Translation Services can still be used but coding against them in Visual Studio results in a warning. This change will not impact any previously created variation labels or the ability to schedule translation activities or workflows based on previously created variation labels. If you create new variation labels no translation will be available for the labels. The steps impacted by this change have been noted below.
Instead of using on-demand, manual translation services, we recommend using Bing translation APIs. The Machine Translation Server API will be marked as deprecated but will be available through the SharePoint CSOM for now. You can find out more about the API in this article on Machine Translation Services in SharePoint.
Important: Neither of these features is a translation tool. MUI changes the display language for the user interface and variations supports creating multiple versions of source content that you can then have automatically translated using machine translation services or manually translated by localization professionals. There is limited support of MUI for custom user interface (UI) elements.
Know the difference between a site’s user interface and content
Websites generally have two parts: The user interface, which is how you interact with the site itself, and the content, which is the information that you keep on the site.
The MUI feature works with your site’s user interface, and the variations feature works with your site’s content.
The user interface of your site refers to the elements on your screen that you use to interact with SharePoint, such as the menus, the navigation items, and the recycle bin.
With the MUI feature, you can display the following user interface elements in different languages:
Site title and description
SharePoint default menus and actions
Custom columns (list or site)
Navigation bar links
Managed metadata services
Note: The MUI feature changes only the display language for default UI elements. Custom UI elements that you have added are not translated.
The variations feature works with your site content – the information you store on a site, but not the site user interface. If the language packs are installed, and MUI has been set up, then UI will appear in the selected language.
The basic content element that the variations feature works with is the page. When you publish the source site, all publishing pages from the Pages library are copied automatically to the targets and queued for translation and publishing. Document libraries, announcement lists, and image libraries are also copied as part of the variations process. List variations are similar to page variations with one exception: you cannot specify individual items for translation. The complete list will be copied to targets and packaged for translation when using human translation or submitted to Microsoft for machine translation. For more information about variations, see Create a multi-language website.
Note: A document library can contain documents in multiple languages without requiring you to create websites or site collections in multiple languages.
When to use MUI, variations, or both features
Decide which multilingual features you are going to use before you begin creating your site collection, for the following reasons:
If you’re going to use the MUI feature, you’ll need to have your server farm administrator install the necessary language packs for every language you want to make available. After the farm administrator deploys language packs, site collection owners can create sites and configure the MUI to display the site user interface in different languages. Individuals can choose to view their sites in the language they want.
After you have created a site, you cannot change its default user interface language, so it’s important to start in the correct language.
If you’re going to use the variations feature, there are specific considerations about how you configure the sites for updating, notification, and other issues that you need to set before you create the sites.
Use MUI only
Use MUI if your site will have users who cannot work in the default language that you plan to use for the site. Use MUI only when you want to allow your users to switch their personal view of a site or web pages after it’s been created in the default language.
Use Variations only
Variations is designed to be used when your content has to be available to people who speak many different languages (or who might need to have specific information that is based on regional differences)—that is, websites that deliver tailored content to suit different cultures, different markets, and different geographic regions.
If you are working in an environment where there are no language packs installed you cannot use the MUI feature, but variations still allows you to set up a content distribution system for multiple languages.
Use both features together
When you are both publishing content to be translated into other languages, and you have site owners who might need to make changes to the site (but who don’t speak the language that the site was created in), then you can use both features together to make both the content and the UI of your sites available in multiple languages.
For example, using the variations feature, you might have created an English source site with a Chinese target. The variations feature sets up the Chinese site based on the language and locale settings. Now, imagine that a US-based site owner who does not speak Chinese needs to make some changes on the Chinese site for maintenance. Using the MUI feature, the English speaker can switch the Chinese site’s UI to English and more easily interact with the site.
When you are planning multilingual sites, you should also consider what locales are necessary to support your sites. Locale is a regional setting that specifies the way numbers, dates and times are displayed on a site. The locale setting does not change the language in which the site is displayed. For example, selecting the Thai locale changes the default sort order of list items and uses the Buddhist calendar instead of the default calendar. The locale is a setting that is configured independently of the language specified when a site is created, but unlike the language, the locale can be changed at any time.