What is the long mark over a vowel called in Latin?

The long mark over a vowel in Latin is known as a macron. This diacritical mark signifies that the vowel it accompanies is pronounced with a longer duration than a short vowel, which is typically indicated by the absence of a mark or a different symbol called a breve. The macron plays a significant role in Latin pronunciation and poetry, as the length of a vowel can affect the meaning of words and the rhythm of verses. Knowing when to apply a macron can also assist learners in the correct pronunciation and understanding of Latin texts.