Memory-Optimized Instances : They provide fast performance for applications that process Bigdata in memory. Memory Optimised instance includes support for enhanced networking, up to 25gbps of Network Bandwidth. They come packaged with EBS installed and optimised.
Use cases are in-memory caches and open-source databases.
Compute Optimised Instances : Compute Optimised instances provide high-performance computing resources and fast batch-processing. They are used ideally for media transcoding, gaming servers, ad-server engines. Compute Optimised Instances use the AWS Nitro system, which combines dedicated hardware and lightweight hypervisors. Just like Memory-optimized, Compute Optimised Instances come with optimised EBS as well.
Accelerated Computing Instances : These Instances use co-processors and hardware accelerators to improve upon the performance. They get used in graphics processing, floating-point calculations, data pattern matching. Accelerated Computing Instances use extra hardware power to combat software limitations and latency. These also support the Elastic Fabric Adapter (EFA)
Storage Optimised Instances : Storage Optimised instances are ideal for workloads that need high sequential read and write. These instances use their local storage to store data.
Storage optimised instances provide low latency and high-speed random I/O operations. They get used in NoSQL databases like Redis, MongoDB, data warehousing.
General Purpose instances provide a mixture of computing, memory, and networking resources. General Purpose Instance find their use in applications that consume multiple resources in equal proportions, for example, web servers, code repositories.