It arose directly from the Greek letter alpha. In the Early Cyrillic alphabet its name was azǔ and it had a numerical value of 1.
In many languages that use Cyrillic, such as Russian, Serbian, Macedonian and Bulgarian, it denotes /a/. It may also represent /ɑ/ and /ə/ in languages such as Ingush and Chechen.
In the romanization systems for the Russian, Bulgarian, and Ukrainian languages, it is romanized as the Latin letter A.
Through history, it has had various shapes, but today is standardised on one that looks exactly like the Latin a (including the italicized form).
| Character encoding | Case | Decimal | Hexadecimal | Octal | Binary |
|---|---|---|---|---|---|
| Unicode | Capital | 1040 | 0410 | 002020 | 0000010000010000 |
| Small | 1072 | 0430 | 002060 | 0000010000110000 | |
| ISO 8859-5 | Capital | 176 | b0 | 260 | 0010110000 |
| Small | 208 | d0 | 320 | 0011010000 | |
| KOI 8 | Capital | 225 | e1 | 341 | 0011100001 |
| Small | 193 | c1 | 301 | 0011000001 | |
| Windows 1251 | Capital | 192 | c0 | 300 | 0011000000 |
| Small | 224 | e0 | 340 | 0011100000 |
Its HTML entities are: А or А for capital and а or а for small letter.