Language selection with flags
The Language selection with flags web part allows users to select which language version of the website's content should be displayed. Corresponding flags are displayed in addition to the names of the available languages. The web part is only visible if there are multiple cultures assigned to the site. To see the web part, you need to add another culture to the website in Site Manager -> Sites -> edit the site -> Cultures.
More information on development of multilingual websites can be found in Kentico CMS Developer's Guide -> Content management -> Multilingual content.