# ASCII

/ˈæski/ (US) · CEFR C1 · Noun

Source: https://englishreference.com/word/ascii
Updated: 2026-05-19

## Definition

a system for representing text as numbers. It uses 128 different characters, including letters, numbers, and symbols, so computers can understand and display text.

For teachers: a standard for representing text as numbers using seven-bit binary code. It defines 128 characters, including control codes and printable symbols, for use in computing and telecommunications.

## Examples

- The file contains only ASCII characters.
- When you send an email, the text is usually converted into ASCII so the recipient's computer can read it.
- While modern systems often use Unicode, many legacy applications still rely on ASCII for basic text processing due to its simplicity and widespread historical compatibility.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.