Das Aufnahmedatum gehört zu den Metadaten.

Because Datum is a neuter noun in German, so its definite article is das.

• das Datum = the date
• therefore das Aufnahmedatum = the recording date / date of recording

In German compounds, the last part usually determines the gender. Since the last part is Datum, the whole compound is neuter.

It is a compound noun:

• Aufnahme = recording, capture, taking, admission (depending on context)
• Datum = date

So Aufnahmedatum literally means something like recording date or date of capture.

This is very common in German: instead of using several separate words, German often combines them into one noun.

The verb is gehören, which often means to belong.

In this sentence, it appears as gehört zu, which means:

• belongs to
• is part of
• is included among

So Das Aufnahmedatum gehört zu den Metadaten means that the recording date is part of the metadata.

Important:

• gehören by itself can mean to belong to someone/something
• zu etwas gehören often means to belong to a group/category

Because the preposition zu always takes the dative case.

• nominative plural: die Metadaten
• dative plural: den Metadaten

So:

• zu + den Metadaten = to / among the metadata

This is a standard pattern:

• zu dem becomes zum
• but in the plural, zu die is not possible; it must be zu den

In German, den can be:

• accusative masculine singular
• or dative plural

Here it is dative plural, because:

1. Metadaten is plural
2. zu requires the dative

So den Metadaten = the metadata in the dative plural.

Metadaten is the plural of Metadatum.

• das Metadatum = one metadata item / one piece of metadata
• die Metadaten = metadata

In actual usage, German often uses Metadaten where English might simply say metadata as an uncountable noun.

So even though English often treats metadata as a mass noun, German commonly uses the plural form Metadaten.

Normally, many German nouns add -n in the dative plural if possible. But Metadaten already ends in -n, so nothing extra is added.

Compare:

• die Bilder → den Bildern
• die Daten → den Daten
• die Metadaten → den Metadaten

So the dative plural article changes to den, but the noun itself already has the needed ending.

Yes. The subject is Das Aufnahmedatum, which is singular, so the verb is also singular:

• das Aufnahmedatum gehört
• die Aufnahmedaten gehören

So gehört is the 3rd person singular form of gehören.

The sentence follows normal German main-clause word order:

• Das Aufnahmedatum = subject
• gehört = finite verb
• zu den Metadaten = prepositional phrase

So the structure is:

Subject + Verb + Rest

This is the standard pattern in a simple German statement.

Because in German, all nouns are capitalized.

So in this sentence:

• Aufnahmedatum is capitalized
• Metadaten is capitalized

This is one of the most noticeable differences from English spelling.

Yes, that is also correct, but it means something slightly different in structure.

• Das Aufnahmedatum gehört zu den Metadaten.
  = The recording date belongs to the metadata / is part of the metadata.

• Das Aufnahmedatum ist ein Metadatum.
  = The recording date is a metadata item.

The first sentence emphasizes membership in a category.
The second emphasizes identification: it says directly what kind of thing it is.

If you wanted to say The recording dates belong to the metadata, you would say:

Die Aufnahmedaten gehören zu den Metadaten.

Changes:

• das Aufnahmedatum → die Aufnahmedaten
• gehört → gehören

Everything else stays the same because zu den Metadaten is already plural.