Answer: On-Demand Instances

## Explanation **On-Demand Instances** are the default pricing model for Amazon EC2 instances. Here's why: - **On-Demand Instances** allow you to pay for compute capacity by the hour or second with no long-term commitments - This is the most straightforward pricing model where you simply launch instances and pay for what you use - No upfront payment or long-term commitment is required - This makes it the default choice for users who are new to EC2 or have unpredictable workloads **Comparison with other options:** - **Savings Plans**: Require commitment to a consistent amount of usage (measured in $/hour) for 1 or 3 years - **Spot Instances**: Offer significant discounts but can be interrupted with short notice when AWS needs capacity back - **Reserved Instances**: Require upfront payment or commitment for 1 or 3 years in exchange for significant discounts When you launch an EC2 instance through the AWS Management Console without specifying any special pricing model, you automatically get On-Demand pricing.

Author: Ritesh Yadav