Alpha (letter)

Alpha (uppercase Α, lowercase α; Greek: Άλφα Álpha) is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter aleph . Letters that arose from alpha include the Latin A and the Cyrillic letter А.

In English, the noun "alpha" is used as a synonym for "beginning", or "first" (in a series), reflecting its Greek roots.

In Ancient Greek, alpha was pronounced [a] and could be either phonemically long ([a:]) or short ([a]). Where there is ambiguity, long and short alpha are sometimes written with a macron and breve today: Ᾱᾱ, Ᾰᾰ.

In Modern Greek, vowel length has been lost, and all instances of alpha simply represent [a].

In the polytonic orthography of Greek, alpha, like other vowel letters, can occur with several diacritic marks: any of three accent symbols (ά, ὰ, ᾶ), and either of two breathing marks (ἁ, ἀ), as well as combinations of these. It can also combine with the iota subscript (ᾳ).

...
Wikipedia