What is the difference between a static Elastic IP and a regular public IP address in AWS?

In AWS, a typical public IP address is assigned dynamically when an EC2 instance is launched and can change upon restart or stop/start of the instance. Such an IP cannot be reassigned to another resource.

A static Elastic IP is a fixed public IP address that you allocate in your AWS account. Its features:

• Persistence: The Elastic IP remains associated with your account until you release it.
• Reassignability: You can attach the Elastic IP to different EC2 instances or other resources as needed.
• Availability management: It provides a stable public address for services, which is important for DNS, firewalls, and clients.

Example: If you have a web server that requires a permanent IP for DNS records, Elastic IP solves this problem, whereas a regular public IP may change after a restart.

Thus, Elastic IP ensures stability and flexibility in managing public IP addresses in AWS.