Amazon EC2 instances pricing types

Amazon EC2 instances pricing types listed below for reference,

Amazon EC2 instances pricing varies for below types,

1. On-Demand Instances
2. Spot Instances
3. Reserved Instances
4. Dedicated Hosts

As mentioned in AWS EC2 Product page below are details of instances pricing,

1. On-Demand Instances
With On-Demand instances, you pay for compute capacity by the hour with no long-term commitments or upfront payments. You can increase or decrease your compute capacity depending on the demands of your application and only pay the specified hourly rate for the instances you use.
https://aws.amazon.com/ec2/pricing/on-demand/

2. Spot Instances
Amazon EC2 Spot instances allow you to bid on spare Amazon EC2 computing capacity for up to 90% off the On-Demand price.
https://aws.amazon.com/ec2/spot/

3. Reserved Instances
Reserved Instances provide you with a significant discount (up to 75%) compared to On-Demand instance pricing. In addition, when Reserved Instances are assigned to a specific Availability Zone, they provide a capacity reservation, giving you additional confidence in your ability to launch instances when you need them.
https://aws.amazon.com/ec2/pricing/reserved-instances/

4. Dedicated Hosts
A Dedicated Host is a physical EC2 server dedicated for your use. Dedicated Hosts can help you reduce costs by allowing you to use your existing server-bound software licenses, including Windows Server, SQL Server, and SUSE Linux Enterprise Server (subject to your license terms), and can also help you meet compliance requirements.
https://aws.amazon.com/ec2/dedicated-hosts/