Qual è la differenza tra arti e makna ?Sentiti libero di rispondere con un esempio.

most of the time, they're used interchangeably. there's only a slight difference between their connotation, specifically in terms of linguistic.

"arti" leans more toward the literal or the exact translation of a word or a sentence derived from foreign languages. which is why you'll hear Indonesian saying "apa arti kata / kalimat ini?" when asking for the meaning of unfamiliar word / sentence they encounter.
while "makna" is more commonly understood as an underlying idea of a sentence or message. much like a meaning that needs to be interpreted before being fully comprehended.

I hope this doesn't confuse you. and since "arti" is broader in meaning and usage, you can play it safe by using "arti" exclusively.