réels

Réels is the plural form of the French adjective réel and can refer to multiple concepts depending on the context. In mathematics, réels denotes the system of real numbers, written as ℝ. The real numbers include both rational numbers (fractions) and irrational numbers, and they form the real line with a natural order. They constitute a complete ordered field, supporting standard arithmetic and analysis, and underpin calculus and the description of continuous quantities. Real numbers can be represented by decimal expansions; every real is the limit of a sequence of rationals, even when the decimal expansion does not terminate or repeat.

In the realm of digital media, Réels (often written Reels in branding) refers to the short-form video format used on Instagram and Facebook. Introduced around 2020 to compete with TikTok, Réels enable users to create, edit, and publish videos with audio, music, effects, and speed controls. They can be discovered via dedicated tabs, shared to feeds or stories, and may incorporate features such as remixing, duets, and branded content. Availability and maximum duration have evolved, with many regions allowing increasingly longer clips, commonly up to 90 seconds.

Usage in French includes grammar and terminology. The masculine plural is réels and the feminine plural is réelles, used in phrases such as nombres réels and valeurs réelles. Outside mathematics, le réel can denote reality in philosophy, and the legal term biens réels refers to real property as opposed to movable property. Thus réels covers both mathematical syntax and broader linguistic uses, as well as contemporary media branding.