Filnavnet følger mappestrukturen.

Because Norwegian, like German, very often forms compound nouns by writing the parts together as a single word.

• fil = file
• navn = name
• filnavn = filename

Then the definite ending is added to the whole compound:

• filnavn = filename / a filename
• filnavnet = the filename

This is very common in Norwegian:

• bok
  • hylle → bokhylle = bookshelf
• skole
  • bok → skolebok = schoolbook

So filnavnet is not unusual at all; it is exactly how Norwegian normally builds this kind of word.

The -et is the definite singular ending for a neuter noun.

The base noun is:

• et filnavn = a filename

When it becomes definite, Norwegian usually adds the article to the end of the noun:

• filnavnet = the filename

So instead of putting the in front, Norwegian often attaches definiteness directly to the noun.

A simple comparison:

• et hus = a house
• huset = the house

Filnavn works the same way:

• et filnavn
• filnavnet

Because in Norwegian, the definite article is usually attached to the noun as an ending.

So:

• English: the file name
• Norwegian: filnavnet

And:

• English: the folder structure
• Norwegian: mappestrukturen

This is one of the biggest differences from English. Instead of saying a separate word like the, Norwegian often marks definiteness by changing the noun itself.

For the same reason: it is a compound noun.

It is built from:

• mappe = folder
• struktur = structure

Together:

• mappestruktur = folder structure

Then the definite ending is added:

• mappestrukturen = the folder structure

In Norwegian compounds, the last part is usually the main noun. Here, the main noun is struktur, so the whole word means a kind of structure—more specifically, a folder structure.

The -en is the definite singular ending for many common-gender nouns in Bokmål.

Here the head noun is struktur:

• en struktur = a structure
• strukturen = the structure

So:

• mappestruktur = folder structure
• mappestrukturen = the folder structure

Even though mappe is part of the word, it is struktur that determines the gender and the ending, because it is the final/main part of the compound.

Because følger is the present tense form of the verb å følge.

• å følge = to follow
• følger = follows / is following

So in the sentence:

• Filnavnet følger mappestrukturen

the verb must be finite, because it is the main verb of the sentence. English does the same thing:

• to follow
• follows

A few more examples:

• Jeg følger regelen. = I follow the rule.
• Han følger planen. = He follows the plan.

Here it is more like conforms to, matches, or is based on.

In a technical context, følge often means that something is in accordance with a system, rule, standard, or pattern.

So Filnavnet følger mappestrukturen suggests something like:

• the filename is based on the folder structure
• the filename matches the folder structure
• the filename follows the folder structure pattern

So yes, it is the same basic verb to follow, but the meaning here is not physical movement. It is more abstract.

The sentence follows normal Norwegian statement word order:

• Filnavnet = subject
• følger = verb
• mappestrukturen = object

So it is:

Subject + Verb + Object

This is the same basic order as in English:

• The filename follows the folder structure.

That makes this sentence fairly straightforward for an English speaker.

The key nouns are:

• filnavn — neuter

  • et filnavn
  • filnavnet

• struktur — usually treated as common gender in Bokmål

  • en struktur
  • strukturen

Because mappestruktur is a compound whose main noun is struktur, it also behaves like en struktur:

• en mappestruktur
• mappestrukturen

This is why the sentence has:

• filnavnet with -et
• mappestrukturen with -en

Grammatically, yes, but it would change the meaning.

• filnavnet følger mappestrukturen = the filename follows the folder structure
• filnavn følger mappestruktur = filename follows folder structure

The version without the endings sounds more general, abstract, or headline-like. In normal prose, if you mean specific things, the definite forms are usually the natural choice.

So the original sentence sounds like it is talking about a specific filename and a specific folder structure, or about those things as identified concepts in the context.

A rough pronunciation guide is:

FIL-nav-net FØL-ger MAP-pe-struk-TOO-ren

A few notes:

• fø has a vowel sound English does not really have; it is similar to the vowel in French peu or German schön
• g in følger is usually pronounced clearly here
• the stress is typically on the first syllable of filnavnet and mappestrukturen, and on the first syllable of følger

If you want a very rough English-style approximation, you might think:

• filnavnet ≈ FEEL-nav-net
• følger ≈ FURL-ger (very approximate)
• mappestrukturen ≈ MAP-peh-strook-TOO-ren

But that is only approximate, especially for ø.