https://github.com/awsdocs/amazon-ec2-user-guide/tree/master/doc_source/concepts.md
Amazon Elastic Compute Cloud (Amazon EC2) provides scalable computing capacity in the Amazon Web Services (AWS) cloud. Using Amazon EC2 eliminates your need to invest in hardware up front, so you can develop and deploy applications faster. You can use Amazon EC2 to launch as many or as few virtual servers as you need, configure security and networking, and manage storage. Amazon EC2 enables you to scale up or down to handle changes in requirements or spikes in popularity, reducing your need to forecast traffic.
Exam Tips:
- On Demand - allows you to pay a fixed rate by the hour (or seconds) with no commitment.
- Reserved - provides you with a capacity reservation and offer a significant discount on the hourly charge for an instance. 1 Year or 3 Year terms.
- Spot - enables you to bid whatever price you want for instance capacity, providing for even greater savings if your app have flexible start and end times.
- Dedicated Hosts - physical EC2 server dedicated for your use, can help you reduce costs by allowing you to use your existing server-bound software license.
- EBS
- SSD
- General Purpose SSD - balance price and performance for a wide variety of workloads.
- Provisioned IOPS SSD - highest performance SSD volume for mission-critical low-latecy or high-throughput worloads.
- Magnetic
- Throughput Optimized HDD - low cost HDD volume designed for frequently accessed, throughput intensive workloads
- Cold HDD - lowest cost HDD volume designed for less frequentle accessed workloads
- Magnetic - previous generation
- SSD