This is the 319th most frequent French word.
preuve
Proof; evidence.
In this sentence, 'preuve' is used in its primary meaning, referring to physical or logical evidence supporting a claim or fact.
La police a trouvé une preuve importante sur les lieux du crime.
The police found significant evidence at the crime scene.
Here, 'preuve' refers to a document or item used as substantiation or proof of a specific aspect, such as identity.
Vous devez fournir une preuve de votre identité au guichet.
You must provide proof of your identity at the counter.
In this example, 'preuve' is utilized metaphorically to suggest that a result (success) acts as evidence of a principle or claim (the benefits of hard work).