fullstop

The full stop is the punctuation mark used to indicate the end of a sentence. It is represented by a small dot and is the character most English-speaking writers recognize as the end of a declarative clause. In British English and many other varieties, the mark is commonly called the full stop; in American English, it is usually known as the period.

Beyond ending sentences, the full stop appears in abbreviations formed from initials (for example U.S., or Dr.). It may follow an abbreviations rule determined by style guides. The symbol also functions in digital contexts as a separator in web addresses and file names, such as example.com or report.pdf. In mathematics and numbers, a similar dot is used as a decimal point in many languages, though some locales use a comma instead.

Historically, the full stop evolved from a medieval dot used to indicate a pause in manuscripts, later standardized by printers and typesetters into the modern punctuation mark. Its shape and function have remained largely consistent, though typographic conventions have varied over time and across languages.

Spacing after a full stop varies by era and style. Contemporary English typography generally prescribes a single space after a period, while older typewriter conventions favored two. The term full stop remains common in British English, while American practice typically uses period in most contexts.