What Is a CDN and How Does It Relate to Object Storage?

A CDN (content delivery network) is a group of servers in many locations that keep copies of your files close to users, so requests travel a shorter distance. It sits in front of your storage, which stays the origin that holds the real copy of every object.

TL;DR:

• A CDN caches copies of content on servers near users, which cuts latency and takes load off the origin.
• It sits in front of an origin such as an S3 bucket and does not replace it, as in AWS's own example pairing CloudFront with S3.
• AIOZ Storage lists a built-in CDN: files are delivered from the nearest peer node, with no separate CDN fee on top of $0.005 per GB downloaded.

Updated Oct 19, 2026: added the built-in CDN described in the AIOZ Storage docs overview and cited the live billing page for delivery pricing.

What Is a CDN?

MDN defines a CDN as "a group of servers spread out over many locations" that "store duplicate copies of data" so the closest server can answer each request. Instead of every request traveling to one origin, wherever it happens to be, a nearby server with a cached copy answers, and MDN puts the reason plainly: "Geographical distance affects latency proportionally."

The content is usually static, such as images, video, stylesheets and JavaScript bundles. These files don't change on every request, so a CDN can hand out the same copy many times.

What Is CDN Storage?

"CDN storage" usually means one of two things, and you should know which one a vendor means. Most often it is object storage that serves as the origin behind a CDN, with the CDN caching popular files at the edge. Some providers also bundle delivery into the storage service itself, so you get one bill and no separate CDN to configure.

In both cases the storage layer keeps the authoritative copy, while the CDN layer, separate or built in, decides how fast that copy reaches the person asking for it.

How a CDN Works: Edge Servers and Caching

AWS describes CDN servers as "intermediary servers between the client and the website server." When a CDN server already has a file cached, it answers the request directly and the origin never sees it. When it doesn't, it fetches the file from the origin, returns it, and usually keeps a copy for the next request. For the same mechanics applied to video, see how a CDN edge node caches content.

MDN adds that serving static assets from a CDN "lowers the request burden on an organization's own servers." Your origin then handles cache misses, dynamic requests and the first request for new files, while the CDN takes most of the repeat traffic.

Where a CDN Sits: In Front of the Origin

AWS says caching lets a CDN "reduce the amount of data an origin server must provide," and its customer example has Reuters using CloudFront with Amazon S3, where CloudFront handles caching and delivery while S3 holds the files.

The pattern is the same on any cloud. Your origin still has to keep every object durably, and the CDN makes the common case faster: a popular file requested again and again from around the world.

Why CDNs Exist: Latency and Load

Two problems push teams toward a CDN. The first is physics, because a request that travels farther takes longer and no server tuning changes that across an ocean. The second is cost, since an origin built to serve every request at peak load is far bigger than one that only handles misses.

A CDN solves both by moving copies instead of the origin, so your users reach a nearby server and your origin gets a small, predictable share of the traffic.

What a CDN Doesn't Fix

MDN lists real downsides. A CDN adds a dependency on a third party, so your site breaks if that CDN goes down or is blocked in a region. It also adds an attack vector, and it can even slow a page, because the browser needs extra DNS lookups and browsers don't share cache between origins.

A CDN also adds no durability, since a cached copy at the edge is not a backup, and if the origin loses a file the cached copies expire with nothing behind them. Your provider's promises about not losing data rest on the origin, which is why durability and availability are worth checking separately.

Do You Need a CDN in Front of Your Object Storage?

It depends on your traffic. A small set of files requested constantly by users spread across the world, such as video, popular downloads or shared static assets, is the case a CDN was built for. A bucket that serves internal tools or one region gets far less from a cache, because few requests repeat.

Price matters too. If your provider charges for egress and your CDN charges again for delivery, you pay twice for the same bytes, so add both lines when you compare. How AIOZ Storage Pricing Works shows a worked example.

How AIOZ Storage Handles It

The AIOZ Storage overview lists a "Built-in CDN" among its key features. It says AIOZ Storage uses the AIOZ Network's peer-to-peer nodes worldwide, "allowing data delivery from the nearest node without needing extra fees for separate CDN services." The static website hosting docs also describe sites served from a bucket with CDN acceleration.

On price, the billing page charges $0.017 per GB-month for storage, billed hourly, and $0.005 per GB downloaded. That download charge is the delivery cost, and there is no second CDN invoice on top of it. Uploading uses the standard S3 API, as in this command from the CLI docs:

export AWS_REQUEST_CHECKSUM_CALCULATION=when_required
aws configure set default.s3.addressing_style path
aws s3 --endpoint-url https://s3.aiozstorage.network cp /path/to/file s3://bucket-name

The first two lines are ours, not from AIOZ's CLI docs. AIOZ Storage rejects uploads without a Content-Length header, which AWS CLI v2.23.0 and later send by default unless you set when_required (AWS CLI environment variables). Path-style URLs (AWS CLI S3 configuration) are needed because bucket subdomains don't resolve. We confirmed both on Oct 19, 2026; a full upload with real keys is not tested yet.

The docs don't publish cache rules, invalidation controls or how a node is picked as nearest. If you need exact cache behavior, test downloads from the regions where your users are before you drop an existing CDN.

Next step: create a bucket and try a public file or a static site, following the Upload Your First Object guide.

Frequently Asked Questions

What does CDN stand for and what does it do?
Content delivery network, a set of servers in many locations that cache copies of content near users, so a nearby server answers instead of the distant origin.

Does a CDN replace the need for storage?
No. A CDN sits in front of an origin, as in AWS's CloudFront and S3 pairing, and the origin keeps the durable copy of every object.

What is the difference between a CDN and an origin server?
The origin is where your data lives for good. The CDN is a cache in front of it that answers what it can and sends misses and dynamic requests back to the origin.

Why does distance matter for CDN performance?
MDN states that latency grows in proportion to distance, so a server closer to the user responds faster no matter how fast either server is.

Does AIOZ Storage include a CDN?
Yes. Its docs list a built-in CDN that delivers data from the nearest peer node without a separate CDN fee. You pay $0.005 per GB downloaded, and the docs don't publish cache or invalidation settings.

What are the downsides of using a CDN?
MDN lists a third-party dependency, an extra attack vector, and possible slowdowns from extra DNS lookups and cache that browsers don't share across origins. A CDN also adds no durability.

When does a CDN help the most?
When the same files are requested again and again by users in many regions, such as popular static files and video. Low-traffic or single-region workloads gain far less.

Related Reading

• How AIOZ Storage Pricing Works - the storage and delivery rates, with a worked cost example.
• Hot vs Cold Storage: Storage Tiers and When They Matter - access frequency, the other big cost lever.
• What Is Amazon S3? Object Storage Explained - the origin model behind AWS's CloudFront and S3 example.
• AIOZ Storage Explained: S3-Compatible Decentralized Storage - what AIOZ Storage is overall.
• What Is CORS and Why It Matters for Object Storage? - the browser rule that decides whether a web app can call a bucket directly.
• Static Website Hosting on AIOZ Storage: Full Setup Guide - a site served straight from a bucket.

References

• AWS: What Is a CDN (Content Delivery Network)?
• MDN Web Docs: CDN (Content Delivery Network)
• AIOZ Storage Docs: Overview
• AIOZ Storage Docs: Billing