Prerequisite

A prerequisite is a condition that must be satisfied before something else can occur. It can refer to knowledge, credentials, or tasks required beforehand. The term comes from Latin prae- “before” and requisitus “required.”

In education, prerequisites are courses or assessments that establish readiness for a more advanced course. They help ensure students have the necessary background. They may be required by institutions, departments, or programs. Examples include Calculus I as a prerequisite for Calculus II, or a placement test determining readiness for a language course. Prerequisites can sometimes be waived for students with prior coursework, demonstrated competence, or through placement exams.

In computing, software prerequisites are packages, libraries, or runtime environments required to install or run a program. These dependencies may specify minimum versions and are often managed by package managers. If prerequisites are not met, installation may fail or the program may not run properly.

In project management and research, prerequisites refer to tasks or conditions that must be completed before subsequent tasks can begin. They are represented as dependencies in project plans and can influence scheduling and the critical path.

Across domains, the concept of prerequisites helps structure progression and ensures the necessary knowledge, skills, or conditions are present before moving forward. A related term is co-requisite, which describes a course that must be taken at the same time as another rather than beforehand.