Glossary
Caching
Caching stores copies of data or pages so repeat requests are served instantly, reducing server work and dramatically speeding up websites.
Caching stores copies of data, files, or rendered pages so that repeated requests can be served quickly without redoing expensive work. It is one of the most effective ways to make a website fast.
Layers of caching
- Browser cache — assets stored on the visitor's device, controlled by
Cache-Controlheaders and influenced byttl. - CDN / edge cache — a
cdnserves cached content from a nearby location. - Page cache — full HTML pages cached on the server (vital for
wordpressand othercmssites). - Object cache — database query results (e.g. Redis, Memcached) reducing
mysqlload. - OPcache — compiled
phpbytecode kept in memory.
Why it matters for hosting
Caching slashes ttfb and server load, directly improving core-web-vitals. The right combination — server, edge, and application caching, often via nginx, litespeed, or a reverse-proxy — is the single biggest lever for performance on dynamic sites.
See also
TTFB (Time To First Byte)
TTFB measures how long after a request the first byte of the response arrives, reflecting server, network, and backend processing speed.
CDN (Content Delivery Network)
A CDN is a worldwide network of edge servers that cache and serve your site close to visitors, cutting latency and absorbing traffic spikes.
Core Web Vitals
Core Web Vitals are Google’s user-experience metrics — LCP, INP, and CLS — that measure loading, interactivity, and visual stability of a page.
WordPress
WordPress is the world’s most popular content management system, powering a large share of websites with themes, plugins, and a PHP/MySQL stack.
Reverse Proxy
A reverse proxy sits in front of web servers, forwarding client requests to them while adding caching, TLS termination, and load balancing.