General
General is the first tab in Settings and has two rows: theme and language. Both apply only to your own user, and both take effect immediately. The same options appear as submenus in the user card at the bottom of the left-hand menu.
Theme
Four themes: light and dark, each with a high-contrast variant. The active theme is marked with a tick. What the four do to the map and the panels is described on Theme.
Language
The list shows the languages your organisation has access to. Norwegian bokmål is the default, English is always available, and nynorsk, Swedish and Danish appear where they are switched on.
The language option controls the interface: menus, tabs, buttons and field names. It does not translate the content of the registers. Names of matrikkelenheter, companies, map layers and datasets come from the sources and stay in the original language whatever you choose here.
Some new fields are put into use before the translation is ready, and they stay in English until the text is in place. If you see an English label where the rest is Norwegian, that is the reason.