What are the two yellow curves in McDonald's most recognizable logo called?

The two yellow curves in McDonald's most recognizable logo are called the Golden Arches.

The arches began as physical architectural features on early McDonald's restaurants. Architect Stanley Meston designed the restaurant's original arches in 1952, and the first locations using the design opened in 1953. From the roadside, the structures were intended to attract motorists and make the buildings easy to identify.

The arches later became a stylized letter M and evolved into a corporate trademark. Jim Schindler created the familiar logo form in 1962 by combining the two arches into a single graphic mark. The design turned an architectural feature into one of the world's most recognizable business symbols.

The term is sometimes used for the logo and for the building elements interchangeably. Historically, however, the physical arches came first, while the familiar flat yellow M developed later as McDonald's branding became more standardized.