An orthography is a set of conventions for writing a language. It includes rules of spelling, hyphenation, capitalisation, word breaks, emphasis, and punctuation.

Some languages use an alphabetic system, such as the Roman system (used for English and all Australian Indigenous languages) or the Cyrillic system (used for Russian). Other types of orthography include syllabic where each symbol represents a syllable (used for Japanese) and logographic, where each syllable represents a concept (used for Chinese)

Orthography is distinct from grammar, which concerns the structure of languages and not their writing.