AWS EC2 (Elastic Compute Cloud) provides virtual servers in the cloud, and its pricing is based on several factors, including instance types, instance usage, operating systems, regions, and additional services. Here are the key components that affect EC2 pricing:

1. Instance Types: EC2 offers various instance types optimized for different workloads, such as general-purpose, compute-optimized, memory-optimized, GPU instances, and more. Each instance type has different specifications and pricing.

2. On-Demand Instances: On-Demand instances are charged by the hour or per-second based on the instance type and the region where the instance is running. With On-Demand instances, you have flexibility and pay for compute capacity as you use it, without any upfront commitments.

3. Reserved Instances: Reserved Instances provide significant cost savings for applications with steady-state or predictable workloads. You can reserve instances for a 1-year or 3-year term, and they offer a lower hourly rate compared to On-Demand instances. The savings depend on the upfront payment and the term chosen.

4. Spot Instances: Spot Instances allow you to bid on spare AWS capacity, offering the possibility of running instances at significantly reduced costs. However, the pricing for Spot Instances is variable and can fluctuate based on supply and demand in the AWS Spot market.

5. Dedicated Hosts: Dedicated Hosts provide physical EC2 servers dedicated to your use, offering compliance, licensing, and control benefits. Dedicated Hosts have an hourly rate, and you can choose between On-Demand, Reserved, or Spot pricing models for Dedicated Hosts.

6. Operating Systems: The choice of the operating system for your EC2 instances can affect the pricing. For example, Amazon Linux and Amazon Linux 2 are provided at no additional cost, while Windows instances incur an additional licensing fee.

7. Additional Services: Additional services such as Elastic Block Store (EBS) for storage, Elastic IP addresses, data transfer, load balancing, and others may have their own pricing models. Make sure to consider these services when calculating your overall EC2 costs.