Website Caching For Decreased Loading Times.
Caching is the saving of specific elements on your website so they do not need to be "re-built". This can be very effective in speeding up your website as these elements do not need to be regenerated.
For example, let's say I ask you to tell me your best friend's phone number. If you have that number memorized, you can just recite it to me to call them. If you don't have it memorized, you will have to look up the phone number and give it to me. The first example where you have the phone number memorized is an example of caching. The second example shows that you did not cache the phone number.
As you can see, the first example delivered the expected result (producing the phone number to call your friend) much faster then having to take the time to go look it up. This same principle can be used in websites too where specific items or even entire pages can be cached so they are just displayed instead of having to go "look up" the items needed in them. There are two levels of caching:
Module Level Caching
For example, in a Joomla website, there may be a module that displays the number of published articles in a single category. If there isn't caching on that module, then the system would have to query the database and ask "how many articles are in this category." The result is then calculated by first filtering to that category, then counting up all of the articles in that category, then delivering that number to the module to be shown on that page. If there is caching on that module, then the last value is taken from when the cache was created. For example, if someone had visited that page 10 minutes ago, and the cache is still valid, the number will be pulled automatically from there - reducing the amount of time needed to generate that element.
Page Level Caching
Page level caching follows the similar principle as above, except not just specific items are cached, the entire page is cached! Meaning that on a visit to the page, the entire page is then generated and then saved in the cache. All of the elements are saved so they can easily be retrived - including dynamic items - so be careful to not cache pages that are meant to look different to specific sets of visitors to your website. Page level caching can significantly speed up your website by not just caching small elements on the page, but the entire page itself! The page cache may take a bit longer to generate on the first visit, but after that, it is served up very fast!
Be Careful With Too Much Website Caching
Too much caching can actually hurt your website. Although, improved speed can help your SEO rankings and user experience, it can also hurt them as well with unintended consequences. To learn more about this, review our article on the dangers of over optimization.
There are other ways to improve your website loading speed!
Check out our article on the other methods to improve the speed of your website.