a1

A1 is a designation used across multiple domains to denote first quality, primary status, or a product name. While the exact meaning varies by context, common threads include grading, branding, and model naming in both consumer and professional settings.

A1 steak sauce is a brown sauce marketed by the H. J. Heinz Company. It is widely used as a flavoring for beef and other meats, and is sold internationally under the A1 brand.

Audi A1 is a subcompact luxury automobile produced by the German manufacturer Audi. Introduced in 2010 as the smallest model in the Audi lineup, the A1 emphasizes urban practicality, efficiency, and premium fittings in a compact form.

The A1 is a major trunk road in the United Kingdom, linking London with Edinburgh and passing through cities such as Peterborough, Newark, and Newcastle upon Tyne. Segments are sometimes designated as A1(M) when portions are built as motorways.

In spreadsheet software, A1 notation refers to the standard method of addressing cells by grid coordinate, combining column letters and row numbers (for example, A1). This system contrasts with R1C1 notation, used in some programs.

A1 is an international paper size in the ISO 216 standard, part of the A-series. It measures 594 by 841 millimeters (approximately 23.4 by 33.1 inches) and is commonly used for posters, drawings, and architectural plans.

In mathematics, A^1 (often written A-one) denotes the affine line, a fundamental object in algebraic geometry representing one-dimensional affine space over a field. It serves as a basic building block for more complex spaces.