What is the difference between VPC security group and EC2 security group

Question

Please share your opinion as how VPC security group and EC2 security group are different from each other.

Answer 1

EC2-Classic

The original release of Amazon EC2

Your instances run in a single, flat network that you share with other customers.

EC2-VPC

The original release of Amazon VPC

Your instances run in a virtual private cloud (VPC) that's logically isolated to your AWS account.

Answer 2

EC2-Classic Security Group

• When the instance is launched, you are given an option only to choose a Security Group that resides in the same region as the instance.
• You cannot change the Security Group after the instance has launched. You have an option to edit the rules.
• They support only IPv4.

EC2-VPC Security Group

• You can change the Security Group even after the instance has launched.
• They are IPv6 Capable