What is Cached Data?
Imagine you have a big book with lots of pages. Reading the whole book every time you need information can take a long time. So, you decide to keep a smaller, quicker-to-read version of the important pages handy. This way, when you need the information, you look at the smaller version first, and if it's not there, you go back to the big book.
In the world of computers, cached data is like that smaller, quicker-to-access version. It's a storage space where your computer keeps copies of information it thinks you might need again, so it doesn't have to go through the slower process of getting the data from the original, bigger source every time.
Caching in Next.js:
In Next.js, caching is a way to store and reuse data to make your website faster. Here's a simple explanation:
Server-Side Rendering (SSR): Next.js can generate the web page content on the server before sending it to your browser. Once it does that, it can save a copy of the page content, or parts of it, in a cache.
Client-Side Rendering (CSR): For parts of your website that change less often, like your homepage, Next.js can save a version of that page on your computer (in your browser's cache). When you visit the page again, it can quickly load that stored version instead of fetching everything from the server.
Why is it Useful?
Speed: Cached data helps your website load faster because it can skip some of the steps needed to get information. It's like having a shortcut to the things your website already knows.
Reduced Server Load: If many people visit your website, caching can help reduce the strain on the server. Instead of generating the same pages over and over again, the server can serve up the cached versions.
Better User Experience: Faster loading times make for a smoother experience for people using your website. They don't have to wait as long for things to show up.
Where is it Used?
Caching is used in many places on the internet:
Web Browsers: Browsers like Chrome, Firefox, and Safari use caching to store website data locally, so when you revisit a page, it can load faster.
Content Delivery Networks (CDNs): These are like special servers worldwide that store copies of websites. When you visit a website, a CDN can provide you with a version of the site that is closer to you, making it load faster.
Server-Side Applications: Next.js uses caching to speed up the rendering of pages on the server and reduce the load on the server.
The storage location of cached data depends on the type of caching being used whether it's server-side caching, client-side caching, or a combination of both.
Server-Side Caching:
For server-side caching, the cached data is stored on the server. This means that the server keeps a copy of generated content or data so that it can quickly serve it to subsequent requests without having to regenerate it.
In the context of Next.js, which supports Server-Side Rendering (SSR), the server may cache the HTML content of pages to serve them more efficiently.
Client-Side Caching:
For client-side caching, the cached data is stored on the user's device (in the browser). This allows the browser to reuse locally stored resources without fetching them from the server again.
Browsers use mechanisms like HTTP caching, where they store copies of responses from the server and reuse them for subsequent requests. This can include caching stylesheets, scripts, images, and more.
Next.js and Caching:
Next.js supports both server-side rendering and client-side rendering, and caching can occur in both scenarios.
Server-Side Rendering: The server may cache the generated HTML pages or components to serve them quickly to subsequent requests.
Client-Side Rendering: Next.js applications can also leverage client-side caching mechanisms provided by browsers, such as caching static assets like JavaScript bundles, images, and stylesheets.
In summary,caching is like keeping shortcuts to information so you can access it quickly without going through the long process every time. In Next.js, it helps make websites faster, especially when they have lots of visitors. Next.js may use server-side caching to store pre-rendered HTML content on the server, and it also allows browsers to cache static assets on the client side. The combination of these caching strategies helps improve the overall performance and speed of Next.js applications.