Object Store is scalable, affordable online storage that works with many tools and is ideal for creating backups, sharing files and hosting static content. At TransIP we offer this in the form of S3-compatible Object Store powered by the OpenStack Swift API.
An S3 bucket is the “top” storage layer in the S3 API: a logical place where you store objects (files + metadata). Inside such a bucket you typically organise objects using prefixes in the object key (e.g. backups/2026/01/file.zip). This looks like a folder structure, but in S3 it’s basically just part of the object name.
In OpenStack Swift that same top layer is called a container: a place where objects live. Swift containers cannot be nested (so no container-in-container).
Bucket vs container: is that the same at TransIP?
On our platform they effectively mean the same thing. Our Object Store platform runs on OpenStack Swift (so “container” is the native concept), but also offers an S3-compatible API. Because of this you will see “buckets” in S3 terminology, while under the hood and in the Horizon web interface they are “Swift containers”.
This is because Horizon uses OpenStack/Swift terminology. In the Horizon UI you therefore manage containers and, inside them, objects. Within the Swift API documentation, however, the term buckets is used exclusively.
Which terminology do I see where?
- In Horizon (Object Store): containers and inside them objects.
- In S3 tools/SDKs (AWS CLI, s3cmd, SDKs): buckets and inside them objects (with keys/prefixes).
Are folders real folders?
Not really: in both S3 and Swift it’s all about objects with names. What looks like “folders” is usually a prefix in the object name/key (e.g. photos/2026/jan/IMG_001.jpg). For that reason you can’t give Swift containers any “sub-containers”.
Which naming conventions apply?
Swift is often more permissive than S3. A name that is allowed in Swift can still be rejected by S3 tooling.
- Swift container name (typical): max 256 bytes and no /.
- S3 bucket name (AWS-style, safest choice): 3–63 characters, lowercase letters only, numbers, dots and hyphens, starts/ends with a letter or number, not formatted as an IP address, etc.