The main Amazon EC2 instance types and how to choose the right one

General Purpose instances have a balanced ratio of CPU, memory and networking, which suits web servers, application servers and small to medium databases. The burstable instances in this category are cost-effective for workloads with occasional CPU spikes.

Compute Optimized instances are meant for CPU-intensive applications such as batch processing, high-performance computing, gaming servers and scientific modeling. They have a higher ratio of compute to memory for tasks that need sustained processing power.

Memory Optimized instances handle workloads that process large datasets in memory, including in-memory databases, big data analytics and enterprise applications. They have much more memory relative to CPU.

Accelerated Computing instances use GPUs or custom accelerators for machine learning training, inference, graphics rendering and other specialized computation.

Storage Optimized instances are built for applications that need high IOPS and low-latency disk access, such as NoSQL databases, transactional systems and data warehousing.

Network Optimized and specialized instances cover high-throughput networking or niche workloads like HPC or macOS development.

In practice, look at CPU utilization patterns, memory requirements, storage performance and network bandwidth before choosing an instance type. If the workload changes, you can change the instance type after stopping the instance.