W1

W1 is an alphanumeric designation used in several different domains; there is no single canonical meaning.

In geography, W1 denotes a central London postal district within the Western (W) postcode area. It covers parts of the West End, including neighborhoods such as Marylebone, Fitzrovia, Soho, and Mayfair. The district is used by the Royal Mail to sort mail and by businesses and residents for addresses and location references.

In mathematics and related fields, W1 is used to denote first-order Sobolev spaces. Typically written as W^{1,p}, with p indicating the integrability exponent; W^{1,2} is common and often identified with the Hilbert space H^1 in many contexts.

In technology and industry, W1 appears as a model or product code—applied to devices, components, or standards. These uses are diverse and usually context-dependent, so it is necessary to consult accompanying documentation to determine the intended meaning.

As a generic alphanumeric label, W1 may refer to other domain-specific concepts. Disambiguation relies on context.