If you have tried to join hotel or airport Wi-Fi, you may have come across the letters VPN. People often say that a VPN makes a connection safer, but that still leaves the obvious question: what does it actually change?
VPN stands for Virtual Private Network. It creates a protected route inside the internet connection you already have. A VPN cannot get you online by itself, so you still need Wi-Fi or mobile service.
The name sounds technical, but the basic idea is not difficult once you follow the route your data takes. We will start with that route, then explain terms such as encryption and IP address as they appear.
Contents
- Quick Answer: What Is a VPN?
- A VPN in 30 Seconds
- How a Normal Internet Connection Works
- What Changes When You Turn On a VPN
- Four VPN Terms Worth Knowing
- What a VPN Can Do
- What a VPN Cannot Do
- A Simple Example for a Trip to Japan
- Is It Legal to Use a VPN in Japan?
- Common Misunderstandings
- Project Torii Verdict
- Frequently Asked Questions
- Sources & Evidence
Quick Answer: What Is a VPN?
Quick answer
A VPN sends internet traffic from your phone or computer to a server run by the VPN provider before it continues to the website or app you are using. It protects the connection between your device and that server. Websites usually see the server’s IP address – the number that identifies the connection – rather than the one assigned by your hotel or mobile network. A VPN does not give you an internet connection, make you completely anonymous, or protect you from every scam or harmful file.
A VPN in 30 Seconds
Without a VPN, traffic from your phone or computer travels through Wi-Fi or a mobile network to the website you want to use. Turn on a VPN, and that traffic goes to a VPN server before it reaches the website.
Normal connection: device -> Wi-Fi or mobile service -> website
A travel eSIM or a physical SIM can provide that mobile service.
VPN connection: device -> protected route -> VPN server -> website
The website now receives the connection from the VPN server. A hotel or airport network may still be able to tell that you are using a VPN, but the contents of the protected route are much harder for the network operator to read.
How a Normal Internet Connection Works
Suppose you open a map while traveling. Your phone must first connect through hotel Wi-Fi or mobile service from a travel eSIM. A VPN comes after that step. If you have no signal and no Wi-Fi, switching on a VPN app will not get you online.
Data from your device travels through a Wi-Fi router or mobile network before reaching the website or app server. Most websites now use HTTPS to protect data moving between your browser and the site. The Federal Trade Commission (FTC) says that public Wi-Fi is usually safe today because most websites use encryption. [6]
A VPN does not replace HTTPS. It is an extra measure that protects the route from your device to the VPN server and reduces what the local network can see.
What Changes When You Turn On a VPN
When you turn on a VPN app, your device sends its traffic through a protected route to a VPN server. That server passes the traffic on to the website, then sends the reply back through the same route. The National Institute of Standards and Technology (NIST) defines a VPN as a virtual network built on top of an existing network. [1]
Two visible details change. Traffic between your device and the VPN server is encrypted, and the website sees the VPN server’s IP address instead of the address assigned by the hotel or mobile network. [4] [5]
The VPN protects the connection only as far as the VPN server. Beyond that point, protection such as the website’s HTTPS still matters. The VPN provider also becomes the organization carrying your traffic. The FTC advises checking its terms and privacy policy before signing up. [5]
In other words, some information that becomes harder for a hotel or airport network to see is now handled by the VPN provider. That is why the company behind the service, its logging policy, and its approach to sharing data matter more than price or name recognition alone.
Four VPN Terms Worth Knowing
Encryption
Encryption changes readable data into a form that cannot be understood without the right way to decode it. A VPN mainly uses encryption to protect traffic between your device and the VPN server. [3]
IP Address
An IP address is a number used to identify where internet data should go and where replies should return. The Internet Corporation for Assigned Names and Numbers (ICANN), the nonprofit organization that coordinates internet names and addresses, describes it as a numerical identifier that helps devices send data to the correct destination. [4]
People often compare an IP address to a street address, but it does not automatically identify one particular person. When you use a VPN, websites will usually see the IP address of the VPN server you are using.
VPN Server
A VPN server is a computer that receives traffic from your device and passes it on to the internet. To the website, the connection will normally appear to come from this server. Some services let you choose a server in a particular country or region, although the choices and behavior vary by service.
VPN Tunnel
A VPN tunnel is the name for the protected route between your device and the VPN server. There is no physical tunnel. It is simply a useful way to picture a private route inside the public internet that makes the traffic within it difficult for outsiders to read. [1] [2]
What a VPN Can Do
- Encrypt traffic between your device and the VPN server, making it harder for nearby network operators to read the contents.
- Reduce the connection details visible to a hotel, airport, or cafe network operator. The network may still be able to tell that you are using a VPN.
- Replace the IP address visible to websites and apps with the IP address of the VPN server.
- Connect you to a workplace network through a VPN specified by your employer. Workplace VPNs may have a different purpose and setup from consumer VPN services.
Which traffic uses the VPN depends on the app and your device settings. Some services support split tunneling, which lets selected apps use the VPN while others use the normal connection.
What a VPN Cannot Do
- Replace Wi-Fi, an eSIM, or a physical SIM. You need an internet connection before a VPN can work.
- Guarantee complete anonymity. An account you are signed in to, cookies (small pieces of data a website saves in your browser), device information, and payment details may still identify you.
- Turn a fake website into a genuine one. The FTC warns that even when the connection to a scam site is encrypted, information you enter still reaches the people running that site. [6]
- Prevent every malicious file, weak password, or piece of information entered after someone tricks you. These are different problems from the route your data takes.
- Guarantee access to a streaming service, bank, game, or booking site. A changed connection may trigger extra verification or a block.
- Guarantee faster internet. Encryption and the extra trip through a VPN server can slow a connection under some conditions. Project Torii has not run speed tests for this article.
| Area | What it can do | What it cannot do |
|---|---|---|
| Connection route | Protects the route from your device to the VPN server | Provides the internet connection itself |
| IP address | Shows websites the VPN server's IP address | Automatically changes your device location or account details |
| Public Wi-Fi | Adds a privacy measure | Stops every fake site, scam, or device problem |
| Anonymity | Reduces information visible to the local network | Guarantees that nobody can identify or track you |
| Service access | May make the connection appear to come from another region | Guarantees access to streaming, banking, or other services |
A Simple Example for a Trip to Japan
Imagine connecting to hotel Wi-Fi to open a map and check your email. This is an example for explanation, not the result of Project Torii testing a connection at a particular hotel.
Even without a VPN, HTTPS websites and many apps encrypt the contents of the connection. When you turn on a VPN, traffic from your device to the VPN server also travels through one protected route, making detailed destination information harder for the hotel network to see.
If you sign in to your email, however, the email provider still knows which account you are using. If you enter your card number on a fake booking site, the site still receives it. A VPN protects the route your data takes; it cannot decide whether the person or business at the other end is trustworthy.
On public Wi-Fi, also check that you have joined the correct network and do not ignore browser security warnings. Keep your device software updated and use multi-factor authentication, which asks for another form of proof, such as a code, as well as your password. VPN04 will cover these precautions in more detail.
Is It Legal to Use a VPN in Japan?
Using a VPN is legal in Japan. The Information-technology Promotion Agency, Japan (IPA) includes using a trusted VPN service, when needed, among its precautions for public Wi-Fi. [7]
That does not make every activity legal. Unauthorized access, copyright infringement, fraud, and other offenses remain illegal when carried out through a VPN. You must also follow your employer’s or school’s rules and the terms set by hotels, networks, and online services. [8]
Common Misunderstandings
| Misunderstanding | What is actually true |
|---|---|
| A VPN gets me online | No. Wi-Fi or mobile service must already be available. |
| A VPN makes me completely anonymous | No. Accounts, cookies, and device information can still provide other clues. |
| A padlock means the website is genuine | The padlock shows that the connection is encrypted. It does not prove that the people running the site are honest. |
| A VPN always makes me look as if I am abroad | The outward-facing IP address changes, but your device location and account region are separate. |
| Any paid VPN is safe | Price is not enough. Check the operator, data use, and logging policy. |
Project Torii Verdict
Verdict
A VPN adds a protected route on top of your existing Wi-Fi or mobile connection. It protects traffic from your device to the VPN server and changes the IP address visible to websites. It does not replace an internet connection or guarantee complete anonymity.
Understanding the technology does not mean that you need a VPN for your trip. If you want help deciding, read Do You Need a VPN in Japan? An Honest Guide for Travelers. You can compare services after you know that a VPN would be useful for you.
Frequently Asked Questions
Can a VPN connect me to the internet by itself?
No. A VPN uses an existing Wi-Fi, eSIM, physical SIM, or fixed connection. If you have no mobile signal and no Wi-Fi, turning on a VPN app will not get you online.
Does a VPN make me anonymous online?
Not completely. The IP address visible to a website changes, but signed-in accounts, cookies, and device information remain. You also need to trust the VPN provider that carries your traffic.
Can a VPN prevent hacking, scams, and malware?
It can help protect the connection route, but it cannot stop every threat. Information entered on a fake site, malicious files, weak passwords, and outdated devices are separate problems.
Can a VPN replace an eSIM or travel SIM?
No. An eSIM or physical SIM connects your device to a mobile network. A VPN changes the route your traffic takes after you are online. You can use both at the same time. VPN03 will compare their roles in more detail.
Does a VPN always change my location?
A website may estimate your region from the VPN server’s IP address. However, a VPN does not automatically change your phone’s GPS location, location estimates based on nearby Wi-Fi or mobile towers, or the country registered to your account. [9]
Will a VPN always work with streaming services or banking apps?
No. A service may restrict IP addresses associated with VPNs or ask for extra verification when a connection looks unfamiliar. You may need to disconnect the VPN, return to your own mobile service, or check the service’s official guidance.
Sources & Evidence
The sources below support the factual claims in this article. Every official page was checked on 11 September 2026. Links and time-sensitive details may change.
| No. | Primary or official source | Claim supported | Scope and limit | Checked |
|---|---|---|---|---|
| 1 | NIST Computer Security Resource Center / VPN glossary | General definition of a virtual network built on an existing network | Technical definition summarized for beginners; does not assess any individual product | 11 Sep 2026 |
| 2 | NIST Special Publication 800-77 Revision 1 / Guide to IPsec VPNs | VPN tunneling and encryption | Focuses on IPsec; does not represent every consumer VPN method | 11 Sep 2026 |
| 3 | NIST Computer Security Resource Center / Encryption glossary | Definition of encryption | General definition; does not assess the encryption or implementation of a particular VPN | 11 Sep 2026 |
| 4 | ICANN / Internet Protocol address | IP addresses identify devices and help deliver data | Introductory definition; does not cover internal addressing in detail | 11 Sep 2026 |
| 5 | Federal Trade Commission / In the market for a VPN app? | Traffic routing, visible connection source, and the need to check the provider | Published in 2018; public Wi-Fi guidance cross-checked against the newer FTC source | 11 Sep 2026 |
| 6 | Federal Trade Commission / Are Public Wi-Fi Networks Safe? | HTTPS, current public Wi-Fi guidance, and scam-site risks | General guidance; does not assess the Wi-Fi at any particular venue | 11 Sep 2026 |
| 7 | Information-technology Promotion Agency, Japan / Telework security advice | Use of a trusted VPN, when needed, as a public Wi-Fi precaution | Official public guidance; not an endorsement of a particular service | 11 Sep 2026 |
| 8 | Japanese Law Translation Database / Act on Prohibition of Unauthorized Computer Access | Definition and prohibition of unauthorized access | Confirms that routing an offense through a VPN does not make it lawful | 11 Sep 2026 |
| 9 | Apple Support / Privacy and Location Services | Devices can estimate location through GPS, Wi-Fi, and mobile towers | Used only to show that location signals exist separately from IP addresses | 11 Sep 2026 |
Official URLs
- [1] NIST Computer Security Resource Center: Virtual Private Network glossary
- [2] NIST Special Publication 800-77 Revision 1: Guide to IPsec VPNs
- [3] NIST Computer Security Resource Center: Encryption glossary
- [4] ICANN: Internet Protocol address
- [5] Federal Trade Commission: In the market for a VPN app?
- [6] Federal Trade Commission: Are Public Wi-Fi Networks Safe?
- [7] Information-technology Promotion Agency, Japan: Telework security advice
- [8] Japanese Law Translation Database: Act on Prohibition of Unauthorized Computer Access
- [9] Apple Support: Privacy and Location Services