What caching actually means
If you’ve worked with a web developer, you’ve probably heard about caching. Maybe you’ve been told to “clear the cache” when something wasn’t working right. It’s one of those terms that gets thrown around with the assumption that everyone knows what it means.
Caching stores your website content so your server doesn’t have to rebuild everything from scratch for every visitor. While that sounds like a technical detail, it has real implications for how your site performs and what it costs to run.
How websites work without caching
When someone visits your WordPress site, your web server receives the request, queries the database for content, runs through your theme files, processes your plugins, assembles everything into a complete page, and sends it to the visitor’s browser.
This involves dozens of database queries and can take several seconds. For a single visitor, it’s manageable. For hundreds of visitors requesting pages simultaneously, your server is doing the same work repeatedly, even when the result is identical every time.
What caching changes
Caching saves the finished result. Once a page has been built, the cached version gets stored and served to subsequent visitors. No database queries. No theme processing. Just delivering the ready-made page.
The impact is immediate. Pages that took three or four seconds to load can drop to under a second. Your server can handle more visitors simultaneously, which matters during traffic surges from social media or marketing campaigns. And because your server does less work per visitor, you’re reducing the computational resources your site needs, which translates to lower hosting costs or the ability to handle more traffic on your existing plan.
Speed affects how people interact with your site. Amazon found that every 100ms of latency cost them 1% in sales[1]. BBC discovered they lost an additional 10% of users for every additional second their site took to load[2]. Faster sites keep visitors engaged.
How different types work together
Your website uses several forms of caching, each handling different aspects of performance.
Browser caching stores images, stylesheets, and scripts on each visitor’s device. When they browse to another page or return later, their browser uses those saved files instead of downloading them again.
Object caching saves frequently-used bits of data that get reused repeatedly. Your navigation menu might require several database queries to construct. Object caching saves the assembled menu so those queries don’t need to run again until something changes.
Page caching stores complete pages on your web server. Instead of building each page from scratch, your server serves the stored version. This is the biggest performance improvement for WordPress sites.
Edge caching distributes your content to servers around the world. Visitors get files from whichever server is geographically closest, reducing the physical distance data travels.
What this means when managing your site
When you update your website and don’t see changes right away, caching is usually the reason. You’ve updated the content, but visitors are seeing the cached version that was saved earlier.
Most of the time, caches clear automatically when you publish updates. Sometimes you need to manually clear the cache using the “Clear Cache” button in your WordPress admin. Understanding that multiple caches work together helps explain why “have you cleared the cache?” is often the first troubleshooting question.
The real-world impact
We regularly see sites go from multi-second load times to under a second with proper caching. That changes how people experience your site.
Speed improvements work invisibly in the background. Once caching is set up correctly, you get the performance and reliability benefits without thinking about it.
If your site takes several seconds to load or your hosting provider sends warnings about resource usage, it’s worth investigating your caching setup. Getting it right early prevents performance problems later.