Object Storage
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Traditional file systems and block devices start to struggle when you need to store billions of large files across many machines: images, videos, backups, logs, exports, and ML datasets. Object storage is built for that kind of scale. It is the model behind services like Amazon S3, Google Cloud Storage, Azure Blob Storage, and MinIO.
The core idea is simple. Object storage does not give your application a disk or a mounted folder. It gives your application an API: store this object under this key, then fetch it later by that key.
That small change shifts the trade-offs. You gain huge scale, strong data safety, HTTP access, lifecycle policies, and low cost. You give up normal file-system behavior such as in-place writes, file locks, and Unix-style file operations.
This chapter explains how object storage works, where it fits in system design, and where it should not be used.