How to delete instance in EC2?

How can I delete instance in Amazon EC2. I have terminated the instance but still it was showing in instance list table. I want to know few things related to this

1: Is there any significant difference b/w Delete and Terminate?
2: what is the use of terminated instance?
3: what are the cases at which instance gets terminated?

1. Terminating your instance is essentially deleting it, it will take some time to get reflected on your dashboard (meaning it won't appear on your instance list table)
2. There is no use of terminated instances.
3. Once you terminated your instances, it means you have completely lost that particular instance.

But if, during the time of creation of your instance, you had enabled the option called Protect against accidental termination, then you will not be able to terminate without disabling this option.

But in your instance table if the Instance State column has the value terminated it means your instance is deleted and you can no longer use it.

The only thing you can do is terminating an instance. It stops everything.

After you terminate an instance, it remains visible in the console for a short while, and then the entry is automatically deleted.

You cannot delete the terminated instance entry yourself.

More info here http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/terminating-instances.html

Shuts down one or more instances. This operation is idempotent; if you terminate an instance more than once, each call succeeds.

Terminated instances remain visible after termination (approximately one hour).

Note By default, Amazon EC2 deletes the Amazon EBS root device volume at instance termination. Additional volumes that were attached when the instance launched and any volumes that were attached after instance launch persist. For more information, see Preserving Amazon EBS Volumes on Instance Termination in the Amazon EC2 User Guide for Linux Instances.