Which alphabet was the first to use vowels and consonants?

During the early first millennium BCE, the Phoenicians, who originated in Lebanon, turned into successful maritime merchants, and they gradually spread their influence westwards, establishing outposts throughout the Mediterranean basin. The Phoenician language belonged to the Semitic branch of the Afro-Asiatic language family, and it was closely related to Canaanite and Hebrew. With them, the Phoenicians carried goods to trade and also another valuable commodity: their writing system.

The Phoenicians had a writing system similar to those used by other Semitic-speaking peoples of the Levant. They did not employ ideograms; it was a phonetic writing system composed of a set of letters that represented sounds. Like the modern Arabic and Hebrew writing systems, the Phoenician alphabet only had letters for consonants, not for vowels.

The Greeks took the Phoenician alphabet and made a few key changes: they dropped those signs for which there was no consonantal equivalent in the Greek language and used them instead for individual vowel sounds. As a result, the Greek vowel letters A (alpha), E (epsilon), I (iota), O (omicron), Y (upsilon) and H (eta), came into being as adaptations of Phoenician letters for consonant sounds that were absent in the Greek language. By using individual symbols to represent vowels and consonants, the Greeks created a writing system that could, for the first time, represent speech in an unambiguous manner.