What is a VPN?

A VPN (Virtual Private Network) is a service that encrypts your internet connection and routes it through a secure server, masking your real IP address. By doing so, it ensures that your online activities remain private and your data is secure, even on public networks.

Why Use a VPN?

1. Enhanced Privacy

Without a VPN, websites, ISPs (Internet Service Providers), and other entities can track your IP address, browsing habits, and location. A VPN hides this information, giving you greater anonymity.

2. Security on Public Wi-Fi

Public Wi-Fi networks are hotspots for cybercriminals. A VPN encrypts your connection, safeguarding your data from prying eyes.

3. Bypassing Geo-Restrictions

VPNs allow you to access content unavailable in your country by routing your connection through servers in different regions.

4. Preventing ISP Throttling

Some ISPs monitor your online activities and slow down your connection based on usage. A VPN encrypts your traffic, preventing ISPs from selectively throttling your speeds.

5. Online Banking

Some banks block access from foreign IP addresses to prevent fraud. A VPN allows you to appear as if you're accessing the internet from your home country by routing your connection through a VPN server in your home country.

To grasp how VPNs work, it's helpful to understand some fundamental networking concepts.

1. Network Interface Card (NIC):

The NIC is the hardware in your computer or device that enables network connectivity.

• Wired NICs use Ethernet cables to connect directly to a network.
• Wireless NICs connect to Wi-Fi networks without cables.

Without a NIC, your device cannot access the internet, making it a critical component for VPN functionality.

2. Network Address Translation (NAT):

NAT (Network Address Translation) is a method used by routers to map multiple private IP addresses to a single public IP address (or a few public IPs).

NAT allows multiple devices on a private network to share a single public IP address, effectively managing limited public IP resources.

Without NAT, every device would need its own public IP address. For example:

• If a single household had 10 devices, it would need 10 public IPs.
• Multiply that by millions of households worldwide, and the demand for public IPs would far exceed supply.

NAT solves this problem by letting networks use private IPs internally and translating them to one or a few public IPs for external communication. This significantly reduces the number of public IPs required globally.

Example

1. The Setup:

Imagine you have a home network with 3 devices:

• Device A: Private IP 192.168.1.2
• Device B: Private IP 192.168.1.3
• Device C: Private IP 192.168.1.4 These private IPs are not unique and cannot be used on the internet. Instead, your Internet Service Provider (ISP) gives you one public IP: 203.0.113.1.

2. Device Wants to Access the Internet:

Suppose Device A wants to visit example.com (IP 93.184.216.34). It sends a request to the router with its private IP address:

• Source IP (Private): 192.168.1.2
• Destination IP (Public): 93.184.216.34.

3. The Router Translates:

The router receives the request and does two things:

• Replaces the private IP (192.168.1.2) with the public IP (203.0.113.1).
• Records the translation in a table:

Private IP  | Port    | Public IP       | Port
192.168.1.2 | 12345   | 203.0.113.1     | 54321

Here, 12345 is the source port assigned by Device A, and 54321 is a new port the router assigns.

4. The Request Goes to the Internet:

Now, the request sent to example.com looks like this:

• Source IP (Public): 203.0.113.1
• Source Port: 54321
• Destination IP (Public): 93.184.216.34. This makes it seem like the request is coming from the public IP, not Device A.

5. Response Comes Back:

The website example.com sends a response back to your public IP:

• Source IP: 93.184.216.34
• Destination IP (Public): 203.0.113.1
• Destination Port: 54321.

6. Router Translates Back:

The router checks its NAT table to match the public IP and port (203.0.113.1:54321) to the corresponding private IP and port (192.168.1.2:12345). It then forwards the response to Device A.
7. Device A Gets the Data:

Device A receives the response, and the process is complete!

VPNs add a layer of privacy to this setup by replacing your public IP with that of the VPN server, preventing websites and other entities from tracking your location and activities.

How a VPN works

Step 1: Establishing a Secure Tunnel

• When you enable a VPN, it creates a secure and encrypted connection (a "tunnel") between your device and a VPN server located elsewhere.
• Encryption ensures that any data traveling through this tunnel is scrambled and cannot be intercepted or read by unauthorized parties.

Step 2: Sending Your Data

• All your internet traffic (like requests to visit websites) is routed through this secure tunnel to the VPN server instead of going directly to the internet.

Step 3: Decryption at the VPN Server

• The VPN server receives your encrypted data.
• It decrypts the data to understand your request (e.g., visiting a specific website).

Step 4: Hiding Your IP Address

• The VPN server forwards your request to the website you're trying to access.
• The website does not see your actual IP address (your location). Instead, it sees the IP address of the VPN server, effectively hiding your real location.

Step 5: Receiving the Website’s Response

• The website processes your request and sends the response (e.g., loading a webpage) back to the VPN server.

Step 6: Encrypting the Data

• The VPN server encrypts the website's response and sends it back through the secure tunnel to your device.

Step 7: Decrypting and Displaying Data

• Your device receives the encrypted data from the VPN server.
• It decrypts the data, making it readable, and displays the content you requested (e.g., the webpage).

However, some VPNs may slow down your internet connection due to the extra step of routing traffic through a remote server. It's important to choose a VPN that offers high-speed servers, especially if you plan on streaming or gaming.

Some free VPNs may track and sell user data to advertisers, defeating the purpose of using a VPN in the first place. Always use a reputable paid service with no-logs policy, but remember that expensive doesn't necessarily equate to higher quality.

Recommended Affiliate VPN Providers

1. Surfshark

Why Choose Surfshark?

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• You can use one Surfshark account to secure every device you own that supports a VPN client.
• Surfshark offers advanced privacy features, including rotating IP and Dynamic MultiHop.
• Surfshark is considered to be competitively priced.

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2. NordVPN

Why Choose NordVPN?

• Large Server Network: Access to a vast number of servers in multiple countries, over 5,500 servers worldwide, allowing for fast connections and diverse location options.
• Advanced Security Features: Utilizes industry-standard encryption protocols like AES-256 for maximum data protection.
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Conclusion

VPNs are essential for maintaining online privacy and security in today’s digital world. This article covered how VPNs work, their benefits, and key networking concepts like NIC and NAT that facilitate secure and efficient connectivity. Whether you’re looking to safeguard your personal data, bypass geographical restrictions, or prevent ISP throttling, a VPN is a great tool. With reliable options like Surfshark and NordVPN, you can ensure your online experience remains private and secure.