Purpose
The Delete on Termination flag determines whether the EBS volume is automatically deleted when the EC2 instance it’s attached to is terminated.

How It Works
When you launch an EC2 instance with attached EBS volumes:
• Root volume (default behavior):
The Delete on Termination flag is set to true by default.
→ This means that when you terminate the EC2 instance, the root EBS volume (the one containing the OS) will also be deleted automatically.
• Additional (data) volumes:
The flag is set to false by default.
→ These data volumes are retained even after the instance is terminated, so you can re-attach them to another instance later.