Source: https://www.todhost.com/blog/how-to-speed-up-your-joomla-website-with-the-caching-system.html

One common problem with Content Mnagement systems (CMS) is that they have load problems. The are slow except you do something about their speed. Fortunately, the developers have introduced a system, called caching, to help mitigate this problem.

Many, especially those who are new to Joomla try to make their Joomla sites run more quickly. They find the caching options which promise to help speed up their site but there are several caching options available and they also need to kknow how to apply each and what they will do to website speed.

This blog post explains what options are available and how you can enable them.

What is a cache?

A cache stores all or part of a web page so that it doesn't have to be pulled from the database. By not needing to connect to the database, a website can respond much more quickly to a visitor.

Does cachingreally help? Yes, absolutely! There are many ways to speed up a Joomla site, but we often see far better results from caching than anything else. As Klas explains in his post, retrieving stored website pages is up to 10 quicker than waiting for them to be created.

Also read: Best Plugins for Faster Loading WordPress Websites in 2016

Useful information about the Joomla cache options

By default caching is not enabled in Joomla. You need to enable the built-in caching features included in Joomla.
Cached content is only displayed to visitors who are not logged into the website. Logged in visitors will not be provided with the cached content.
It does not apply to the Administrator area of the website.
All cached content is stored and retrieved from the /cache/ directory.
Caching is split into the following key areas page caching, View and Module caching.
The system cache plugin takes precedence over global configuration and module cache settings.

Also read: How to Reduce Website Bounce Rate

How does the web cache work?

Joomla wants to present the fastest user experience possible to the visitor. As someone clicks through the site, Joomla makes snapshots of where they have been and saves them to a temporary directory. If the person wants to return to a previous location, the server grabs the temporarily saved page, which should be faster than going back to the data base and generating an entire new page which will load all plugins and extensions. The temporary page is like a static page and so it loads faster.

Sometimes this cache doesn't get cleaned out soon enough, so when you make a change in the administrator area then go to the front end to view it, you're actually looking at an "old" page that hasn't been updated yet.

Read also 16 Mistakes That Turn People Away From Your Website

To make the update apparent, you need to delete the temporary copy and force the browser to build a new page.
This gets double complicated because not only does Joomla make temporary pages, but your browser does as well. So even though you cleared Joomla cache, you may still have to clear your browser cache to see the changes. Clearing the browser cache may not be necessary if the browser cache system is not enabled.

You can minimize the effects of Joomla cache by clearing it occasionally, or you could just turn it off while you are developing and making changes. You can turn it back on again after you publish the live site.

Also read: How to Prevent the most common Application Attacks against websites

Caching Options

Option #1: Cache Settings
Go to System > Global Configuration > System. You'll see an area called Cache Settings with these three options:
• OFF - Caching disabled
• ON - Conservative caching
• ON - Progressive caching

Here's the default tooltip explaining the difference between the two options.
• Conservative caching: smaller system cache.
• Progressive caching: faster, bigger system cache, includes module renders cache. Not appropriate for extremely large sites.

Read full log post at: https://www.todhost.com/blog/how-to-speed-up-your-joomla-website-with-the-caching-system.html