Temporary Internet Files and Cache?????

Please!!! Reply my questions in simple to read and step by step instructions if need be. I’m a “NEWBIE”.
I downloded “The Touble With Windows 95/98 from this site. I’ll write a part of the article I don’t understand, what does it mean?
“REMEMBER THAT THE TEMPORARY INTERNET FILES ARE YOUR BROWSER CACHE. (what’s this browser cache thing?) THIS CACHE HAS BEEN ACCUSED OF CAUSING ERRORS WHILE SUTFING, AND IT MAY BE A GOOD IDEA TO EMPTY THIS CACHE FROM TIME TO TIME, BUT MAKE SURE YOU WON’T REGRET IT WHEN VISITIG YOUR FAVORITE SITE.” (what does that mean?