Editing A

'''A''' (named ''a'') is the first letter and the first [[vowel]] of the modern [[Latin alphabet]] and the [[ISO basic Latin alphabet]]. Its design is historically derived from the [[Greek alphabet|Greek]] letter [[alpha]], which was in turn adapted from the [[Phoenician alphabet|Phoenician]] letter ''[[aleph]]''.

In English orthography, "A" represents several distinct vowel sounds depending on stress and syllable structure, ranging from the [[open front unrounded vowel]] to various diphthongs.

== Historical Development ==
The letter's visual typography underwent significant structural transformations across ancient Mediterranean writing systems.

=== Epigraphic Roots ===
* '''Egyptian Hieroglyphs and Proto-Sinaitic:''' The earliest ancestor of the glyph was a pictogram representing an ox's head.
* '''Phoenician Standardization:''' Around 1000 BCE, Phoenician scribes simplified the ox head into a triangular shape turned sideways, naming it ''aleph'' (meaning "ox").
* '''Greco-Roman Adaptation:''' When the Greeks adopted the alphabet, they flipped the letter upright to create '''[[Alpha]]''' (Α), using it to denote a vowel sound rather than a glottal stop. The [[Etruscans]] subsequently transmitted this glyph to the [[Romans]], establishing its contemporary capital form.

== Typographic Forms and Variants ==
In modern typesetting, the lowercase "a" typically appears in two primary variants:
* '''Double-storey 'a':''' The standard form used in most printed and digital Roman typefaces, featuring a top bowl and lower loop.
* '''Single-storey 'ɑ':''' The handwritten form (and standard in many italics), consisting of a simple circle with a vertical stroke on the right.

== Applications Across Disciplines ==
Apart from its linguistic function, the character serves as a standardized scientific and cultural notation:
* '''Mathematics and Logic:''' Often used to represent constants, primary variables, or universal quantification ($\forall$).
* '''Computer Science:''' Hexadecimal digit representing the decimal number 10, and hexadecimal ASCII code 0x41 (capital) / 0x61 (lowercase).
* '''Medicine and Biology:''' Designates [[Blood type|blood group A]] under the ABO system, as well as [[Vitamin A]].
* '''Music Theory:''' Represents the pitch [[A (musical note)|A]] (also known as La), serving as the standard reference frequency (A440 = 440 Hz) for instrumental tuning.

== Character Codes ==
{| class="wikitable"
! System !! Character !! Decimal !! Hexadecimal
|-
| ASCII Uppercase || A || 65 || U+0041
|-
| ASCII Lowercase || a || 97 || U+0061
|-
| UTF-8 Fullwidth Uppercase || Ａ || 65313 || U+FF21
|-
| UTF-8 Fullwidth Lowercase || ａ || 65345 || U+FF41
|}

== See also ==
* [[Alpha]]
* [[Aleph]]
* [[Open front unrounded vowel]]

== References ==
<references />

[[Category:Latin-script letters]]
[[Category:Vowels]]
[[Category:Symbols]]