ultimativ
ultimate
The best, most extreme, or definitive thing in a particular category; impossible to surpass.
Für viele Gamer ist dies das ultimative Spielerlebnis.
For many gamers, this is the ultimate gaming experience.

ultimate
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ultimate
The best, most extreme, or definitive thing in a particular category; impossible to surpass.
Für viele Gamer ist dies das ultimative Spielerlebnis.
For many gamers, this is the ultimate gaming experience.

The word 'ultimativ' (ultimate) is closely related to the noun 'das Ultimatum' (the ultimatum). Both come from the Latin word 'ultimus', which means 'the last'. This explains both meanings: the last, final demand and the final, best example of its kind.
Er stellte ein Ultimatum, das nicht ignoriert werden konnte.
He issued an ultimatum that could not be ignored.
In the meaning 'das Beste' (the best), 'ultimativ' (ultimate) is often used in advertising, in the media, or in colloquial speech to describe something as unbeatable. It often has a promotional or exaggerated tone.
Der Hersteller verspricht das ultimative Reinigungsergebnis.
The manufacturer promises the ultimate cleaning result.
In the meaning 'endgültig' (final), 'ultimativ' (ultimatum-like) usually appears with nouns such as 'Forderung' (demand), 'Bedingung' (condition), or 'Warnung' (warning). The context is often formal and expresses that there is no further possibility for negotiation.
Die Gewerkschaft überreichte dem Arbeitgeber eine ultimative Forderung.
The union presented the employer with an ultimatum-like demand.
absolute / absolutely
'absolut' and 'ultimativ' can both be very strong words. 'absolut' means that something applies completely, entirely, or without restriction. It is often used as an intensifier with many adjectives and statements. 'ultimativ' refers more to the best, most extreme, or unsurpassable thing in a particular category. The words can be confused because both sound like 'very strong'. But 'absolut' says: completely and without exception. 'ultimativ' says: the highest or best example of its kind.

Für lange Zugreisen ist dieses leichte Kissen der ultimative Begleiter.
For long train journeys, this lightweight pillow is the ultimate companion.
Nach der Besprechung war mein Kollege absolut überzeugt von dem neuen Plan.
After the meeting, my colleague was absolutely convinced by the new plan.