Glossary

Media offloading means storing your WordPress images and files in cloud storage and serving them to visitors from there, rather than from your web server. It reduces the work and disk your server needs for media. A plugin handles the copying and changes the addresses your pages use.

S3-compatible storage is object storage that accepts the same programming interface as Amazon S3. A tool that can talk to S3 can talk to it too, usually after changing the address and keys. Cloudflare R2, Wasabi, Backblaze B2, DigitalOcean Spaces and MinIO are examples.

Egress fees are what a storage provider charges when data leaves its network. For a WordPress site, that means visitors downloading your images and files. Providers set this differently: some charge per GB, some include an allowance, and some charge no fee. For a busy site, it can be the largest part of the bill.

A bucket is a named container for files in cloud storage. It's like a top-level folder with its own address, permissions and settings. You create one in your provider's dashboard, and your files sit inside it. Names follow rules, and on many providers a name is shared by everyone.

An access key is the pair of values that lets software use your cloud storage without your password: an access key ID, which identifies it, and a secret access key, which proves it. It can do only what its permissions allow, so a key for one bucket can't touch anything else.

A CDN, or content delivery network, keeps copies of your files on servers around the world and answers each visitor from a nearby one. You don't need one to offload media, because your bucket can serve files by itself. It helps most when your visitors are far from your bucket's region.