A false positive is a result that reports a problem that does not actually exist. In security scanning, an example is a tool that marks a server as vulnerable when the relevant fix has already been applied. The opposite error, a false negative, is a real problem that the tool fails to report.
Version-based checks are a common source of false positives. A scanner may read a version string and compare it with the version where an upstream project fixed a flaw, without knowing that the operating system vendor backported the fix into a package that still has an older number. Misreading a header, scanning a different system than intended, or matching a pattern that appears in harmless content can also produce wrong results.
A false positive should not be ignored just because it is inconvenient. The right step is to verify it. Equally, a clean result does not prove you are safe, because scanners can miss problems through false negatives, limited visibility or incomplete tests. Neither a pass nor a fail from a single tool is the final answer.
To check a finding, identify which component the scanner actually examined, compare the installed package with the vendor security notice for your release, and confirm the running version on the system itself. Record the reason when you dismiss a result so the same alert does not need to be re-investigated, and review dismissed findings again after relevant changes.