This kind of template is available for Email and SMS messages and useable in standalone mode, within a workflow or in a recurring delivery.
In the multilingual feature templates, the language management is based on variants. Each variant represents one language.
Adobe Campaign comes with a default language which is set to EN. The default language could be changed to another variant but should be never deleted.
During the template creation, you can add the number of variants corresponding to the number of needed languages in the message.