What does "cached" page mean?

Question

What does "cached" page mean?

Answer 1

When you visit a web page, the files that make up the page are downloaded and saved locally on your computer.  These files are said to be "cached" on your computer.  Thus a "cached" page is one that is saved locally on your computer.  

This is done to speed up the web browsing experience.  Whenever you click the "back" button you are most likely accessing the cached version of the page since its much faster to access the files from your computer than download them a second time.