Patch
A software update released by a vendor to fix a security vulnerability or bug.
A patch↗ is a piece of software a vendor releases to fix a specific problem in an existing program, usually a security vulnerability↗, but sometimes a bug or performance issue. Applying a patch is often as simple as accepting an update prompt on your phone, computer, or app.
The danger isn't that vulnerabilities exist, every piece of software has some, it's the gap between a patch becoming available and it actually being installed. Attackers routinely scan the internet for systems that haven't applied a known patch, since the fix itself often reveals exactly what was broken. Turning on automatic updates wherever possible is one of the single most effective security habits available to anyone.