EC2 Instanceshigh

• Uses EC2 RunInstances API instead of Nova servers.create.
• Requires predefined instance type selection.
• Supports per-second On-Demand billing and Spot/Reserved options.
• Includes hibernation state not standard in OpenStack.

Virtual Machineshigh

• Uses Azure Resource Manager (ARM) REST API at /providers/Microsoft.Compute/virtualMachines instead of OpenStack Nova API at /v2.1/servers.
• Tightly integrated with Azure services like Azure Active Directory for authentication, unlike OpenStack's Keystone.
• VM creation requires specifying size from predefined series with hardware-specific features (e.g., AMD/Intel/ARM), not custom flavor configs.
• Billed per second with complex pricing tiers based on series/reservation options, vs OpenStack's typically hourly or usage-based.

Dropletshigh

• API surface is DigitalOcean’s proprietary REST/CLI/Terraform tooling rather than OpenStack Nova/Neutron/Glance APIs (Droplets are managed via DigitalOcean UI/CLI/API/Terraform).
• Billing is usage-based with per-second billing (60-second minimum and monthly cap) rather than the typical per-hour, quota-based charge model users often see in OpenStack-based clouds.
• Droplets include a bundled outbound transfer allowance with each plan (starting at 500 GiB/month) rather than a separate bandwidth quota/metering model users often encounter in OpenStack deployments.
• Droplets are described as Linux-based VMs on virtualized hardware with local SSD storage, whereas OpenStack deployments commonly expose distinct block storage (Cinder) and image services (Glance) and may not bundle bandwidth/monitoring/firewalls into the instance offering.

VM instanceshigh

• Uses REST API 'instances.insert' instead of Nova 'servers.create' with different auth via service accounts vs Keystone.
• Supports bare metal instances (no hypervisor), not in standard OpenStack Nova.
• Network interfaces tied to VPC subnets; differs from Neutron ports/floating IPs.

Cloud Servershigh

• Servers provisioned individually via Hetzner API (hcloud), not OpenStack Nova flavors; fixed instance types like CX11 (1 vCPU, 2GB RAM, 20GB NVMe).
• No flavor customization; choose from predefined shared/dedicated vCPU series.
• Billing hourly with monthly cap per server (e.g., €3.29/mo cap for CX11), charged even when powered off until deleted, unlike typical OpenStack stop-to-pause billing.
• Custom REST API at api.hetzner.cloud/v1/servers instead of OpenStack Nova /v2.1/servers (different auth, payloads, response formats).