externally

Externally is an adverb that denotes something concerning, happening, or located outside or on the exterior of something. It contrasts with internally, which refers to the inside or inward aspect. The term is commonly used to describe outward appearance, external influences, or actions taken from the outside.

In everyday language, externally describes features or processes that are visible or originate outside a system. Examples include externally visible branding, externally funded research, or externally sourced materials. It can also indicate that a condition or effect is observed from the outside of a body or object.

In computing and information security, externally oriented usage refers to components or services that are accessible from outside a protected boundary, such as externally facing APIs, externally accessible networks, or externally referenced resources. In medicine and biology, externally applied therapies or devices are placed on the surface of the body, for example topical creams or external fixators.

Etymology: externally derives from external, itself from Latin externus “outside,” via Old French extern. The suffix -ly forms the adverb. The term has been in English use since the early modern period.

See also external, externality, externalization.