On

On is a common English preposition used to denote position in contact with a surface, support, or location. It can express physical contact: for example, a book lying on a table, or being on a street as you walk. It also indicates surface or proximal relation and is used with times and dates, as in on Monday or on Christmas Day, and with states or conditions, such as on duty or on track. In addition, on functions as a particle in phrasal verbs, as in put on or turn on.

As a proper noun, On refers to On Holding AG, a Swiss company known for designing athletic footwear and apparel. Founded in 2010, the brand emphasizes a cloud-like cushioning technology in its running shoes and has grown into an international company. On is publicly traded on the SIX Swiss Exchange and the New York Stock Exchange under the ticker symbol ON.

In postal and administrative usage, ON is the two-letter abbreviation for Ontario, the Canadian province, used in mailing addresses, vehicle registration, and related contexts.

In technology and daily life, on denotes the active state of a device or circuit, as in a switch being on rather than off. It also appears in various idioms and expressions, such as on purpose, on schedule, or on trend.

Etymology traces the preposition back to Old English and Proto-Germanic roots, with cognates in related Germanic languages, reflecting its long-standing role in indicating relation, position, and timing.