What is the function of language keys in Liferay?

In Liferay, language keys play a crucial role in internationalization and localization by allowing the retrieval of localized text. This means that when developing applications or themes, developers can use language keys to reference specific text strings stored in property files. Depending on user preferences or browser settings, Liferay can then substitute the appropriate text in the user's language.

For instance, if an application needs to display a button labeled "Submit," the developer would use a language key associated with that label. Liferay then looks up the corresponding value in the relevant language file (such as Language_en.properties for English or Language_es.properties for Spanish) and presents the text in the user's selected language. This functionality ensures that applications can serve a diverse user base by adapting to different languages seamlessly, enhancing the overall user experience.

In contrast, the other options do not align with the role of language keys. Generating unique component IDs, managing user sessions, or encrypting sensitive data involve different mechanisms and systems within Liferay, not related to localization. Thus, the primary function of language keys is specifically to retrieve localized text, which is essential in making applications accessible and usable across various languages and regions.