What is a cache (Snapchat)? (Mobile phone, internet, smartphone)

Hi there,

I have an important question, but nowhere can I find the right answer or one that is easy to understand.

What does clearing cache mean? on the smartphone?

Are all data then gone from the browser, including bookmarks and saved pages? Is that something like formatting? or is it just the data in the cache that is gone? I would have to empty the cache, because I keep getting reports of regional blocks on Chrome, but I’m afraid that my pages etc. will then be lost.

Thanks very much