Instance Typeshigh

• Fixed predefined configurations only; no custom flavor creation.
• Extensive families for GPU/HPC/ARM etc.
• InstanceType as string param in API, not ID reference.
• Tied to specific hardware generations (Nitro/Xen).

VM sizeshigh

• Predefined hardware-optimized series (e.g., D-family general purpose) with complex naming (e.g., Standard_D4as_v5), not user-defined vCPU/RAM like OpenStack flavors.
• Sizes listed via API /providers/Microsoft.Compute/locations/{location}/vmSizes, region-specific availability.
• Includes accelerator features (GPU, FPGA) baked into sizes, unavailable in basic OpenStack flavors without extensions.
• Cannot create custom sizes; selection from catalog, limiting flexibility vs OpenStack flavor creation.

Droplet sizes (plans)high

• A Droplet must select a predefined “size” bundle (RAM/vCPU/disk/transfer) rather than choosing from an OpenStack flavor catalog that many clouds let you customize/extend at the project level.
• The size object exposes explicit monthly pricing (price_monthly) and per-hour pricing (price_hourly) in the API response, whereas OpenStack clouds typically separate pricing from the Nova flavor definition.
• DigitalOcean sizes embed transfer allowance and region availability directly in the size metadata, while OpenStack flavors generally describe compute resources and rely on separate networking/quotas/policies for bandwidth and availability.
• DigitalOcean size classes are described in the API as categories like Basic, General Purpose, CPU-Optimized, Memory-Optimized, and Storage-Optimized rather than OpenStack’s provider-defined flavor naming/extra-specs approach.

Machine typeshigh

• Organized by families/series (e.g. N2 general-purpose); OpenStack flavors flat list.
• Custom types +5% premium for N/E series; no such billing in OpenStack.
• Naming 'n2-standard-4'; shared-core bursting types absent in OpenStack.

Server Typeshigh

• Fixed predefined types (e.g. CX11, CPX31) with shared_vcpu (noisy neighbors) vs dedicated_vcpu.
• GET /v1/server_types lists all; no custom flavor creation like OpenStack.
• Includes pricing (hourly/monthly net/gross), included_traffic, architecture (x86/amd64/arm).
• Resize via change_type action, but limited to compatible types.