require

Require is a verb meaning to deem something necessary or essential, or to demand that a condition be met. It expresses obligation or necessity, as in "This task requires concentration" or "A visa is required for entry." The noun form, requirement, denotes a condition or prerequisite; to be required means to be mandated or necessary.

Etymology: From Middle English, via Old French requerre, from Latin requirere "to seek again", re- + quaerere "to seek". The sense "to demand" developed in English during the medieval period.

Computing usage: In programming, require refers to a directive that loads code from another file or module. In Ruby, require loads a library or file. In PHP, require and require_once include a script and produce a fatal error if the file cannot be found, with require_once preventing multiple inclusions. In Node.js and many CommonJS environments, require('module') loads a module at runtime; in browser-based module systems, similar functions exist under different names (for example, RequireJS).

Although related, the general English "require" and its programming use are distinct; context clarifies whether it refers to obligation or to code-loading.