Introduction: The Temporary vs. The Permanent
In the world of AWS and other cloud providers, they don't just say 'IP address'. They give you two choices: a **Standard Public IP** or an **Elastic IP**. To a beginner, they look exactly the same—a list of four numbers. But under the hood, they act very differently. Picking the wrong one could mean your website goes offline the next time you reboot.
In this guide, we'll compare the two side-by-side so you can choose the right one for your project.
Public IP: The Rent-a-Room
A standard public IP is like a hotel room. It is given to your 'Instance' (your virtual server) for free the moment you turn it on. However, if you 'Stop' the server and start it again, the cloud provider takes that room back and gives it to someone else. Your server gets a totally new IP. It is perfect for short-term testing but terrible for a live website.
Elastic IP: The Home Mortgage
An Elastic IP is a permanent identity. Once you claim one, it is yours. Even if you shut down your server for a month, that IP sits in your account waiting for you. When you turn your server back on, it instantly 'Re-attaches' to that same IP. It is the gold standard for production websites, API gateways, and mail servers.
Which Should You Use?
- Desktop/Dev Testing: Use a **Public IP**. It's easy, automatic, and free.
- Production/Live App: Use an **Elastic IP**. It ensures your domain settings never break and your customers always find you.
Conclusion
The difference is all about 'State'. Public IPs are dynamic and temporary; Elastic IPs are static and persistent. Check your IP's persistence here.