Updated: April 15, 2022
Sure, website, browser, and server caching all help to decrease your WordPress site’s page load times.
But are they all the same thing?
They’re not, and here’s more detail and the differences between a site cache, browser cache, and server cache.
Before we get into the different types of cache, let’s define the actual word first.
What is Cache (Web Cache)?
A web cache, (pronounced “kash”), is where temporary data, such as photos, webpage formatting, and text, is saved to provide the information faster the next time it’s needed..
How Cache Works
When a visitor arrives at your website, their browser requests information from the server. They must then wait for the server to return the relevant data before seeing your content.
A web cache is data from a website that a computer has temporarily saved for quick and simple future access. You might notice a slight difference in speed if you visit a website that you’ve never visited compared to returning to that site.
The browser must submit fresh requests every time a visitor arrives on your site if web caching is not enabled. If your material has been cached, your server or visitors’ browsers can instead deliver a static duplicate of it.
The Pros and Cons of Caching Your Website
Caching minimizes the number of queries that are sent to your server, which takes longer to process than cached results. This is the main reason for caching and how it may improve page performance, load time, and better user experience.
While load times are crucial, caching also lowers network costs. It is necessary to cache your website’s content in many places between the browsers of your users and your server. When your site’s data is cached closer to consumers’ locations, it consumes fewer resources. This lessens the load on your server and may save you money on network fees.
Other benefits include:
- Speed influences SEO
- Fast sites are easier to crawl
- Avoids network congestion
- Page speed impacts conversions
- Fast sites reduce the bounce rate
Despite all the advantages of employing a cache, there is one little disadvantage that might cause problems for your visitors.
The primary downside of caching is that a client may be viewing old data, which might occur due to your website being cached, but not the server or the browser.
If the cache strategy is not precisely specified, and not configured appropriately, the browser will be unable to validate the cached content and the website may load outdated content, which can negatively influence the user experience.
These flaws may be discovered in both the browser cache and the server cache, so it’s important to understand how they function, especially if your website distributes time-sensitive content regularly.
What Is The Difference Between Cache And Cookies?
Although cookies and cache are both methods of storing data, there are differences between these two, and they serve different functions:
- A cookie is used to save information in order to track various user choices such as browsing sessions to trace the user preferences, password, browser, IP Address, date and time of visit, etc. Whereas a cache is intended to speed up the loading of web pages.
- • Cookies typically expire after a certain period of time, whereas cache is retained on the user’s browser until actively erased by the user.
Click the following article to learn more about the difference between cookies and cache.
Now that we know what cache is, let’s get into the what are the different types of cache and how each works
What are Site, Browser, and Server Caches?
It’s helpful to demystify what site, browser, and server caches are before breaking each of them down by their differences. Knowing what they are can help to make their differences more pronounced.
What follows are details on each of these types of caches.
What is a Site Cache (or Page Cache)?
A site cache, also known as an HTTP or page cache, is a system that temporarily stores data such as web pages, images, and similar media content when a web page is loaded for the first time.
It remembers the content and is able to quickly load the content each time the web page is visited again.
It works similarly to a person’s memory. Once you memorize something such as the answer to 12 x 12, you can easily recall it later when someone asks you for the answer.
Plus, you’re able to repeat the answer quickly each time.
When a user visits a page for the first time, a site cache commits selected content to memory. When that same page is visited again, the site cache is able to recall the same content, then load it much quicker when compared to the first visit. Each visit to the same page is also loaded just as quickly from the cache.
When you use site cache to do this, it’s referred to as “caching.” Site caching is the concept of caching from the client’s side.
This means caching that’s completely taken care of, and controlled by the end-user. A website has only a limited way of administering client-side caching. It can tell a cache how long to store saved data.
That way, a page with content that doesn’t change often can be set to expire later on in the future. But, a page with images that are changed often, for example, can be requested to expire much sooner, or when the page is updated.
This ensures the end-user can regularly see fresh content. But, pages that haven’t changed can still be loaded from the cache to speed up the time it takes to load the page.
For details, check out Caching for WordPress, Explained in Plain English.
What is a Browser Cache?
A browser cache is a kind of client-side cache, which means it’s also a type of site caching. It works in the same way and it’s a cache system that’s built into a browser.
Files and content that are saved are stored on your computer and are grouped with other files associated with the browser you use.
A browser cache temporarily saves these kinds of content:
- HTML pages
- CSS stylesheets
- Other types of multimedia content
According to Google, every browser has some form of browser cache. Although, some have a more comprehensive system such as those found in major options, such as Chrome, Safari, Firefox, and other similar browsers.
As mentioned earlier, a website can communicate with a user’s browser. So, when a page is updated and the content stored in the cache is obsolete, the browser knows it should flush out the old content and save the updates in its place.
The end-user can also manually clear out their browser’s cache whenever they want.
What is a Server Cache?
A server cache is a type of cache that’s related to site caching, except instead of temporarily saving content on the client-side, it’s stored on a site’s server. Server caching is also fully handled and administered on the server with no involvement of the end-user or a browser.
Types of server caching include, but aren’t limited to:
- Object caching – Storing database queries in a server-side cache for quick retrieval on subsequent page loads.
- CDN caching – A Content Delivery Network (CDN) is a cluster of servers that are geographically located all around the world. The cache content that’s loaded using the server that’s closest to the end-user for much faster loading times.
- Opcode caching – PHP code is compiled between each request, then stored in a cache so it’s executable faster on repeated page loads.
Using a server cache for temporary storage is called server-side caching, or can be referred to as “caching” for general use in conversation.
Site Cache vs Browser Cache vs Server Cache
Now that website, browser, and server caching have been defined, you may be able to detect the differences. But laying them all out can be helpful to better understand them.
Here are the main details on caching:
- A cache temporarily stores content for faster retrieval on repeated page loads.
- Using a cache for storage is called “caching.”
Below are the differences between each kind of cache, summarized for clarity:
- A site cache saves certain types of content and is controlled client-side.
- A browser cache saves the same types of content, and is saved on your computer, through your browser, and is controlled by the browser. It’s a type of client-side cache.
- Server caches store content, code, queries, or similar data on a server, or multiple servers, and is controlled by the server instead of a browser (client), or user.
What Kinds of Content Can Be Cached?
Although many websites, WordPress plugins, and CDN solutions use caches primarily to store static objects like images, modern solutions allow for the caching of dynamic content, partially dynamic pages, and even HTML documents, which are the first pieces of information a browser must receive before it can begin building a web page. The following are three types of content in terms of caching:
Items that are commonly cached are as follows:
- Static Images
- Other multimedia content (Video, logos, PDF, gifs, etc)
- CSS stylesheets
Items that can be cached but are rarely cached:
- Full HTML Documents
- API Requests
The following files should not be cached:
- User data, such as order history and account information. Any sensitive information.
Caching with WP Rocket
WP Rocket is a powerhouse WordPress caching plugin that specializes in page caching. It’s a popular option among WordPress experts. If you’re wondering what’s the best caching plugin for WordPress, you’ll likely find helpful information on our dedicated page.
WP Rocket also installs like most other plugins. Once you activate it in a couple of clicks, you’re already set up and ready to go. Site caching for your WordPress website and WP Rocket’s browser caching rules are automatically enabled and optimized without you having to lift a finger.
Although, there are plenty of additional options in case you want to get even more caching powers to further speed up your site’s load times.
You can enable caching for desktop and mobile devices and toggle caching for logged-in users, and you can set the expiry time for the cache.
There are also advanced file optimization options that can significantly improve site performance, including:
- Optimize Google Fonts – combines, preloads, and loads the Google Font file asynchronously automatically.
- Minify CSS files – Minifying CSS removes whitespace and comments to reduce the file size.
- Optimize CSS delivery – Optimizing CSS delivery eliminates render-blocking CSS on your website for faster perceived load time. Option to either load CSS asynchronously or remove unused CSS (preferred method)
It’s a perfect caching solution for WordPress that’s consistently maintained and improved upon with loads of detailed documentation, and expert, helpful support.
Bonus: You can also integrate the CDN of your choice for even more caching superpowers. You can integrate with existing CDNs or use our RocketCDN for unlimited bandwidth at an affordable price. There are loads of options like Batman’s utility belt, except WP Rocket is so much easier to set up and implement.
With so many different types of caching options to speed up your WordPress site, it can be difficult to wrap your head around all of them. That includes what a site, browser, and server cache all happen to be.
Fortunately, you should now be up to speed. No pun intended.
What types of caching do you use? Are there other types of caching that you’re unsure of what they are, or the differences between them? Share your thoughts in the comments below.