The difference between Dernier and Final

When used as adjectives, dernier means final, last, whereas final means last.

Final is also noun with the meaning: a final examination.

check bellow for the other definitions of Dernier and Final

Final as a noun (North America):

A final examination; a test or examination given at the end of a term or class; the test that concludes a class.
Final as a noun (sports):

The last round, game or match in a contest, after which the winner is determined.
Final as a noun:

A contest that narrows a field of contestants to ranked positions, usually in numbered places (1st place/prize, 2nd place/prize, etc.) or a winner and numbered runners-up (1st runner-up, etc.).
Final as a noun (phonology):

The final part of a syllable, the combination of medial and rime in phonetics and phonology.
Final as a noun (music):

The tonic or keynote of a Gregorian mode, and hence the final note of any conventional melody played in that mode.

Final as an adjective:

Last; ultimate.

Examples:

"'final solution; the final day of a school term"
Final as an adjective:

Conclusive; decisive.

Examples:

"a final judgment; the battle of Waterloo brought the contest to a final issue"
Final as an adjective:

Respecting an end or object to be gained; respecting the purpose or ultimate end in view.
Final as an adjective (grammar):

Expressing purpose; as in the term final clause.
Final as an adjective (linguistics):

Word-final, occurring at the end of a word.