OCR GCSE Computer Science Paper 2 Practice 2026 - Free Practice Questions and Study Guide

The character set that consists of 256 characters and is commonly used for 8-bit encoding is Extended ASCII. Extended ASCII expands upon the original ASCII character set, which only contained 128 characters, by utilizing the full 8 bits available in a byte. This allows for an additional 128 characters, bringing the total to 256. These additional characters include various symbols, accented letters, and control characters that are useful for multiple languages and graphical text representation.

In contrast, ASCII alone does not account for the full range of characters available in an 8-bit format, which limits its usability for various languages and systems requiring broader character sets. UTF-8, while capable of encoding a vast number of characters, uses a variable-length encoding scheme that ranges from 1 to 4 bytes, making it unsuitable for a simple 256-character set description. Similarly, ISO 8859 refers to a series of character sets with specific enhancements, but each ISO 8859 variant corresponds to different groups of languages rather than standardizing around 256 characters in a single encoding form related to Extended ASCII.