Browser cache is local storage where a web browser keeps fetched content, such as images, scripts, and pages, so it can load them faster on later visits. It is a normal performance feature, but it also creates security-relevant artifacts on the endpoint.
In cyber attacks, cached files can become hiding places or staging points for malicious content. A browser may store an image or other file that looks harmless in transit, yet that local copy can later be reused, decoded, or inspected by malware or an operator. This matters because defenders who only monitor live network traffic may miss activity that has already landed on disk. In hunts and incident response, browser cache can reveal downloaded payloads, second-stage content, or evidence of user interaction. Defenses often include endpoint inspection, cache artifact review, and controls that detect suspicious file handling, rather than treating cached web content as benign by default.