Public and Private IP Explained in Simple Terms
When you connect to the internet, your device is assigned an IP address (Internet Protocol address). This works like a digital tag that identifies your device and tells other systems where to deliver data. However, not all IP addresses are alike—some are private and used only within local networks, while others are public and used on the internet. Knowing the difference makes it much easier to understand how your devices talk to each other and stay connected.
What is a Public IP Address?
A Public IP address is the globally unique address assigned to your device (or your router) by your Internet Service Provider (ISP). It allows your device to communicate with servers and other devices on the internet.
Example: When you visit google.com, your public IP tells Google’s servers where to send back the webpage data.
Key Points about Public IPs:
- Assigned by your ISP.
- Unique across the entire internet.
- Used for communication outside your home or office network.
- Can be IPv4 (e.g.,
103.25.202.44) or IPv6 (e.g.,2405:204:3012::1).
What is a Private IP Address?
A Private IP address is used within a local network (LAN), such as in your home or office. These are not visible on the internet directly. Instead, they are used for communication between devices like your laptop, smartphone, printer, or smart TV inside the same network.
Example: Your Wi-Fi router assigns your phone a private IP (e.g., 192.168.1.5). If your phone needs to access the internet, the router translates this into the public IP address using NAT (Network Address Translation).
Key Points about Private IPs:
- Assigned by your router.
- Not unique across the entire internet (the same ranges are reused in many local networks).
- Used only inside private networks.
- Free and reusable.
Reserved Ranges of Private IP Addresses
Private IP addresses follow specific reserved ranges:
- Class A:
10.0.0.0 – 10.255.255.255 - Class B:
172.16.0.0 – 172.31.255.255 - Class C:
192.168.0.0 – 192.168.255.255
Any IP address outside these ranges is public.
Key Differences Between Private and Public IP
| Feature | Public IP | Private IP |
|---|---|---|
| Visibility | Visible on the internet | Used only within local networks |
| Assignment | Assigned by ISP | Assigned by router (DHCP) |
| Uniqueness | Always unique across the internet | Can be the same across different LANs |
| Cost | Provided by ISP, may cost extra for static | Free (reusable ranges) |
| Security | Exposed to internet, requires firewalls | More secure, not exposed directly to internet |
| Example | 49.207.62.15 | 192.168.1.1 |
Why Do We Need Both?
- Public IPs are necessary for connecting your local network to the wider internet.
- Private IPs help save the limited IPv4 address space by allowing many devices to share a single public IP.
Without this distinction, billions of devices could not communicate efficiently.
How to Find Your IP Address
Find Public IP:
- Search “What is my IP” on Google.
- Your ISP-assigned public IP will appear.
Find Private IP:
- On Windows: Run
ipconfigin Command Prompt. - On Mac/Linux: Run
ifconfigorip a. - On Mobile: Check Wi-Fi settings.
Conclusion
In short:
- Public IP = Your network’s identity on the internet.
- Private IP = Your device’s local identity inside home/office network.
Your public IP is the address your network uses to connect with the internet, while your private IP is what your individual devices use to talk to each other inside your home or office. Both work hand in hand to keep you connected smoothly and securely.