confinement

Confinement is the state or act of keeping someone or something within bounds or under restraint. The term is used across fields to describe restrictions of movement, position, or freedom, and may refer to physical enclosures, legal custody, medical isolation, or cultural practices that govern daily life.

In law and criminal justice, confinement commonly denotes detention or imprisonment by authorities. It may occur in prisons, jails, or under house arrest, and can be a component of a sentence, a protective custody measure, or immigration detention.

In medicine and public health, confinement often means isolation to prevent transmission of illness. Hospital confinement may involve bed rest or restricted movement; quarantine restricts movement of people exposed to disease. Cultural practices of postpartum confinement involve restricted activity for a period after birth.

In physics, confinement describes limits on the extent or behavior of particles. Color confinement in quantum chromodynamics states that quarks and gluons cannot be isolated; only composite particles such as mesons and baryons exist. Confinement also appears in nanostructures and optical systems that restrict spatial degrees of freedom, affecting how particles or excitations are observed.

The term is used broadly to emphasize restriction or enclosure in both everyday and technical contexts, reflecting a common concern with controlling spaces, movements, or states.