What is a Cloud Instance?

A cloud instance is a virtual server that runs on a cloud provider’s hardware with computer resources such as CPU, memory, and storage. Instead of buying physical hardware, a user will launch cloud instances on demand and pay for what they consume. 

Instances are created and managed using a hypervisor. The hypervisor abstracts the physical hardware and provides a virtualization layer that allows the cloud provider to run multiple instances on a single physical server (host).

For example, Amazon Web Services (AWS) has EC2 Instances, Microsoft Azure has Virtual Machines, Google Cloud has Compute Engine instances, etc. In general, instances are there to run applications, databases, or development environments, or scalable web services.

What are the different types of cloud instances?

Choosing a cloud instance that fits your needs involves workload characteristics, cost implications, and awareness of scalability potential. Here are some of the key factors to consider:

• General Purpose Instances: Balanced compute, memory, and networking performance. Best suited for web servers, small databases, and development/test environments (e.g., AWS t3 or Azure D-series).
• Compute-Optimized Instances: High CPU-to-memory ratio designed for compute-intensive workloads such as batch processing, high-performance web servers, and scientific simulations (e.g., AWS c6i or GCP C2).
  Memory-Optimized Instances: Large memory allocation for applications requiring in-memory processing, such as real-time analytics, caching, or in-memory databases like SAP HANA (e.g., AWS r6i or Azure E-series).
• Storage-Optimized Instances: High IOPS and throughput for workloads that demand fast and consistent disk performance, such as big data, data warehousing, and large transactional databases (e.g., AWS i3 or GCP Local SSD-based instances).
• GPU Instances: Equipped with graphics processing units for tasks like machine learning training, AI inference, video rendering, or 3D modeling (e.g., AWS p4d or Azure NC-series).
• High Performance Computing (HPC) Instances: Optimized for tightly coupled, compute-heavy tasks such as molecular modeling, weather forecasting, and fluid dynamics simulations.

What is the difference between a cloud instance and a virtual machine?

A virtual machine (VM) is a software emulation of a physical computer, usually located on a hypervisor, on premises, or hosted in a private data center, regardless of type or configuration. A cloud instance is an emulation of a physical computer (a VM essentially) that resides within a cloud provider context; it has been provisioned and managed within the cloud provider scope. A cloud instance also offers expanded capabilities over VMs, it may:

• have a pricing model based on utility usage,
• include elasticity in capacity, and
• be globally available.

All cloud instances are forms of VMs, but not all VMs are cloud instances.