ensemble

Ensemble is a term with origins in French, meaning "together" or "as a group." Broadly, it refers to a set of elements considered as a whole, often sharing a purpose or appearance. The word is used across disciplines with specialized senses.

In music, an ensemble is a group of musicians or singers performing together. Sizes range from duos and trios to quartets, nonets, and large orchestras. Ensembles emphasize balance and unity of interpretation, and they may perform with or without a conductor. Repertoire spans classical, jazz, folk, and contemporary works.

In theater and film, an ensemble cast features multiple principal actors with equally important roles. The emphasis is on collaborative interplay rather than a single star guiding the performance.

In fashion, an ensemble is a coordinated outfit designed to be worn as a single look.

In statistics and machine learning, ensemble methods combine multiple models to improve prediction. Techniques include bagging, boosting, and stacking. Ensembles help reduce error by trading variance for bias or vice versa, and they are widely used in classification and regression.

In physics and chemistry, an ensemble describes a large collection of microstates used to model systems at equilibrium. In meteorology, ensemble forecasting uses multiple simulations to quantify forecast uncertainty.

The core idea across uses is a coherent collection designed to function as a unified whole.