Cache for a website: a thorough guide

A temporary repository of resources that are quickly downloaded and retrieved with each request-essentially, we can define the cache and caching activity in this way, i.e., the process of storing certain resources locally so that they can be reused without the need for a full round-trip request pass to the server. Caching can prove to be a crucial element in the optimal functioning of a website and its performance, and in this in-depth guide we will explore the concept of caching, its purpose, how to manage it, and common problems associated with it.

What is the cache

Caching is a process of temporarily storing copies of files, images, Web pages, and other elements in an easily accessible location to reduce the loading time when a user visits a Web site. Resources such as HTML, CSS, images and JavaScript can all be cached.

The term “cache” comes from French and means “to hide” or “to store.” In the context of websites, cache refers more specifically to different types of temporary storage, such as browser cache, server cache, or Content Delivery Network (CDN) cache.Each type of cache has a specific role in speeding up page loading and improving the user experience.

Regardless of the type, in fact, the cache remains a temporary storage mechanism useful for storing data that is frequently used, with the aim of reducing the time needed to access it. Cached pages are provided as static HTML versions to avoid potentially time-consuming queries to the database: publishing the most recent version of a page might, for example, require accessing database information, and this takes longer than publishing an already archived (cached) version of the page.

And so, specifically, a website’s cache is used to store a copy of web pages and their content in order to decrease loading time and, as mentioned, improve the user experience.

How the caching mechanism works: the three main modes

But suboptimal caching does not only mean a bad user experience, because it also means worsening the dialogue with Google crawlers, precisely because of the specifics of this process. To better understand, we need to analyze the 3 main types of caching, their characteristics and the ways they affect each other.

  1. Server-side caching

Server-side caching works by temporarily storing responses to dynamically generated requests and content on the server’s own infrastructure rather than on a client-side device. This type of caching can be useful if we have a site that publishes content that changes frequently, but can be equally stored temporarily to reduce page load time.

The advantage is that we have control over the storage settings, and in particular we can define different cache times for different files (and file types) on the site, evaluating the user’s need to see the latest version of that file. For example, front-page HTML content should probably be cached more often than the background image or style sheet.

The frequency of caching depends on the type of site in question: a news site might require a cache update with each user visit, and everything must be evaluated by examining the market niche, the content of the site, and even the similar actions of competitors.

Cache management is regulated by assigning an expiration label, which allows the browser to know how long an item can be retained and reused, and when to request it again from the server. Setting cache duration correctly will speed up load times for users-which is why Google suggests configuring a one-year validity period for most static resources. By adopting advanced version control techniques for resources, we will also be able to use longer cache durations: if the name of a file changes, the server will automatically request the new file from the server without drawing on the previously cached version. If we do not