A cache is a high-speed, temporary data storage layer used by computers, browsers, and applications to store frequently accessed data, allowing future requests for that data to be served faster. It acts as a "shortcut" for your device, storing images, scripts, and other data from websites or apps so they do not have to be downloaded again, improving overall performance and loading times.
Go to Safari in Settings, then tap "Clear History and Website Data". Clear your cache and cookies on iPhone - Apple Support
Clearing cache and cookies helps protect your privacy, especially on shared devices. How to Clear Cache (Examples):
If apps or websites are running slowly, acting sluggish, or showing outdated information, clearing the cache can often resolve these issues.