Cloud storage breaks into three fundamental types: object, block, and file. Each serves different use cases and has distinct performance and cost characteristics.
Object Storage
Object storage holds unstructured data — files, images, backups, logs, static assets — as flat objects accessed via HTTP/S APIs. Virtually unlimited scale, no hierarchy beyond buckets and keys.
| Provider | Service | Pricing (standard tier) |
|---|---|---|
| AWS | S3 | ~.023/GB/month |
| Azure | Blob Storage | ~.018/GB/month |
| Cloud Storage | ~.020/GB/month | |
| DigitalOcean | Spaces | .020/GB/month, 250GB free |
Features to compare: storage classes (hot/cold/archive), replication, lifecycle policies, versioning, access control, event notifications, and CDN integration.
AWS S3 is the de facto standard with the broadest ecosystem integrations. Most tools assume S3 compatibility. Azure Blob and GCS offer comparable features. DigitalOcean Spaces and OpenNebula deployments can use S3-compatible APIs.
Block Storage
Block storage attaches to virtual machines as raw disk volumes — equivalent to a hard drive. High performance, low latency, but tied to a specific VM.
| Provider | Service | Notes |
|---|---|---|
| AWS | EBS | SSD (gp3, io2) and HDD tiers; multi-attach for io2 |
| Azure | Managed Disks | Premium SSD, Standard SSD, HDD |
| GCP | Persistent Disk | Standard, Balanced, SSD, Extreme |
| OCI | Block Volumes | High performance for database workloads |
Oracle Cloud stands out for block storage performance in database scenarios, with OCI Block Volumes offering consistently high IOPS at competitive pricing.
File Storage
Managed file systems with NFS or SMB/CIFS protocols — shareable across multiple VMs simultaneously.
| Provider | Service | Protocol |
|---|---|---|
| AWS | EFS | NFS |
| AWS | FSx | SMB (Windows), Lustre (HPC) |
| Azure | Azure Files | SMB, NFS |
| GCP | Filestore | NFS |
Choosing the Right Type
- Object storage — backups, media, static websites, data lakes, logs
- Block storage — database data files, OS volumes, high-IOPS applications
- File storage — shared configuration, CMS media, legacy lift-and-shift applications needing shared file systems
Cost Considerations
Egress fees are a significant hidden cost in cloud storage. Data transfer out to the internet typically costs .08–.09/GB on major providers. DigitalOcean Spaces and Cloudflare R2 offer zero egress fees, which matters for content-heavy workloads.