What are all these AWS EC2 instance types?

AWS offers a variety of EC2 instances with different strengths and purposes. General purpose machines like m* include the m1.* and m3.*. Memory-optimized machines like M2 are suitable for memory-intensive applications, while compute-optimized types such as c1.*, c3.*, cc2.*, and cr1.* are designed for calculation-intensive tasks. Graphical application instances include g2* and cg1.*. High storage instances (hs1.*) and high I/O instances (i2.* and hi1.*) are also available. The t1.* instance type is a low-cost option for testing applications. EC2 instances can be launched as PV or HVM, with some offering Enhanced Networking support when started as HVM inside a VPC. Choosing the right EC2 instance depends on factors such as cost and performance requirements, with m1.* being a good starting point for Cassandra clusters. As cluster size grows, consider moving to larger instances like m1.*.xlarge to improve performance and reduce costs.