We probably all know how to clear a Browser Cache to view the latest updated Version of a Webpage. This is something we can do locally on our Computer or Laptop. But Servers also cache Pages sometimes and I have seen instances where the Server or Provider has not cleared cache for a couple of days.

So what is the difference between Server and Browser Cache?

Browser Side Caching: Your web browser (Chrome, Firefox, Safari, or whatever you use) decides to remember how a webpage looks like so it doesn’t have to ask the server to send the webpage again. This saves time (and bandwidth) by eliminating almost the entire network communication. However, if the server decides to change the way the webpage looks like, you’re in trouble because the browser’s “memory” of how it thinks the page should look like is now out of date, and it’ll give you an old version of the page instead of the new one. This is why people sometimes tell you to “clear your browser cache”– that forces your browser to “forget” what the page looks like. This forces it to ask the server for the new, updated version of the page.

Server Side Caching: The server responsible for generating the webpage (i.e. putting the webpage together), decides to remember how the webpage looks like, so it doesn’t have to generate it again. This saves time (but not bandwidth) because now the server doesn’t have to go through the trouble of constructing a whole page– it can just re-send whatever it sent last time the browser asked for it. However, if any data on the webpage needs to change, the server is forced to throw away its “memory” of what the page looks like, and it will need to generate the page again. This kind of caching is useful if the page is really complex and takes a lot of time to generate