enthalten
to contain
To have something as a component or part of the contents.
Diese Sauce enthält Knoblauch und verschiedene Kräuter.
This sauce contains garlic and various herbs.

to contain / abstain
Loading your saved state.
to contain
To have something as a component or part of the contents.
Diese Sauce enthält Knoblauch und verschiedene Kräuter.
This sauce contains garlic and various herbs.

'Enthalten' (to contain / abstain) is an inseparable verb. The prefix 'ent-' remains firmly attached to the verb 'halten' (to hold) in all tenses and sentence positions.
Der Bericht enthält alle wichtigen Informationen.
The report contains all the important information.
The two main meanings are easy to distinguish: if the verb appears with a reflexive pronoun ('sich enthalten'), it means 'to abstain' or 'to refrain from'. Without a reflexive pronoun, it means 'to have as contents'.
Die Schokolade enthält Nüsse.
The chocolate contains nuts.
This meaning is very commonly used to talk about ingredients in foods, components of products, or information in texts.
Dieses Shampoo enthält keine Silikone.
This shampoo contains no silicones.
The phrase 'sich enthalten' (to abstain) is often used in formal contexts such as votes. The thing one refrains from is often in the genitive (very formal) or expressed with 'von' + dative.
Er enthielt sich eines Kommentars zu der Situation.
He refrained from commenting on the situation.
to have
'haben' and 'enthalten' can both say that something is present in a thing. 'haben' is more general and very common in everyday speech: 'Eine Tasche hat viele Fächer' (a bag has many compartments), 'ein Text hat Fehler' (a text has mistakes). 'enthalten' is more precise when something is part of the contents, for example in a drink, a package, a contract, or a file. The words can be confused because 'enthalten' often feels like a more precise version of 'haben'. If you are only naming a feature, 'haben' is more natural. If you are talking about the contents, 'enthalten' is more precise.

Die Reiseunterlagen enthalten alle wichtigen Informationen zum Flug.
The travel documents contain all the important information about the flight.
Der neue Kalender hat genug Platz für meine Termine.
The new calendar has enough space for my appointments.