What is browser cache?
In order to speed up web browsing, web browsers are designed to download web pages and store them locally on your computer's hard drive in an area called "cache". Browser cache (also know as Internet cache) contains records of every item you have viewed or downloaded while Internet surfing. So when you visit the same page for a second time, the browser speeds up display time by loading the page locally from cache instead of downloading everything again.
Although storing Internet cache makes web browser faster as it usually takes your computer less time to display a web page when it can open page's elements or even the entire page from your local Temporary Internet Files folder, You sometimes want to overrule the Internet cache, for Example to see changes you made to a webpage you just uploaded.
In the Safari app on your Mac, choose Safari > Preferences, click Privacy, Manage Website Data, select one or more websites, then click Remove or Remove All.
Removing the data may reduce tracking, but may also log you out of websites or change website behavior.