A targeted piece of software code released by a vendor to correct a specific defect or security vulnerability in an operating system, application, or firmware. In IT infrastructure, applying these updates is a routine maintenance task meant to stabilize systems, though administrators often test them first to ensure they do not break existing functionality.
Heard on the job
We need to schedule a maintenance window to apply the security patch to the core routers.
Insider tip
System administrators joke that a patch just replaces old bugs with new ones, which is why staging and testing are mandatory before rolling them out to production.