EC2

Fixed Performance Instances (e.g. M3, C3, and R3)

Burstable Performance Instances
    - T2
    - Accrue CPU Credits when they are idle
    - It stores them in its CPU Credit balance for up to 24 hours.
    - If and when your t2.small needs to burst to more than 20% of a core, it draws from its 
    CPU Credit balance to handle this surge seamlessly

Cluster
- R4, X1, M4, C4, C3, I2, I3, CR1, HS1, P2, G3, F1, and D2 instances support cluster networking. 
Instances launched into a common cluster placement group are placed into a logical cluster that provides high-bandwidth,

EBS ( Elastic Bean Storege ) Volumes

-  Magnetic volumes provide the lowest cost per gigabyte of all EBS volume types
- General purpose
- Provisioned IOPS (SSD) volumes offer storage with consistent and low-latency performance, and 
are designed for I/O intensive applications such as large relational or NoSQL databases
EBS-optimized Instances
- Dedicated throughput between Amazon EC2 and Amazon EBS, with options between 500 and 4,000 Megabits 
per second (Mbps) depending on the instance type used
- C4, M4, P2, G3, and D2 instances this feature is enabled by default at no additional cost
- Provisioned IOPS volumes can achieve single digit millisecond latencies and are designed to deliver 
within 10% of the provisioned IOPS performance 99.9% of the time.