Encapsulation

Encapsulation is the act of enclosing something within a capsule, shell, or enclosing boundary. In science and engineering, the term is used across disciplines to describe a protective or functional enclosure that confines a substance or component.

In software engineering, encapsulation is the bundling of data with the code that operates on it, and the restriction of direct access to some of an object's components. It is a core principle of object-oriented design that promotes information hiding and modular interfaces, typically using access modifiers and well-defined interfaces. Benefits include reduced coupling, clearer responsibilities, and easier validation of state; drawbacks can include boilerplate and reduced flexibility if overused.

In biology and medicine, encapsulation refers to enclosing substances in a protective capsule or vesicle. This includes encapsulated drugs designed for controlled release, microencapsulation of flavors or enzymes, and the natural capsules around joints or certain cells. Encapsulation can provide protection, targeted delivery, and controlled interaction with the surrounding environment.

In chemistry and materials science, encapsulation protects active materials or controls release by enclosing them in polymers, liposomes, or inorganic shells. Applications range from pharmaceutical delivery and agrochemicals to food additives and cosmetics, where encapsulation improves stability, masks taste, or enables sustained delivery.

Across fields, encapsulation supports modularity, protection, and controlled interaction, but it can add processing complexity. The concept is closely related to abstraction, information hiding, and encapsulated design patterns in software. See also data hiding, modularity, and controlled exposure of interfaces.