Quick answer
A VPN client on your device encrypts your traffic and sends it through one persistent connection — the tunnel — to a VPN server. The server decrypts it and forwards it to the destination as if the request came from the server itself. Responses travel the same path in reverse. Everything between your device and the server sees only encrypted data addressed to one host.
The details — how the tunnel is negotiated, which protocol frames the packets, how DNS is handled, and which traffic enters the tunnel — are what separate a good VPN from a frustrating one.
Step by step: the life of a request
- The handshake. When you press connect, the client and server authenticate each other and agree on session encryption keys. Modern setups complete this in a round trip or two.
- The tunnel interface. Your operating system gets a virtual network interface. From that moment, apps do not need to know a VPN exists — they send traffic normally, and the system routes it into the tunnel.
- Encryption and framing. Each outgoing packet is encrypted and wrapped in the VPN protocol's framing, then sent to the server over the open network. An observer sees packets to one IP address with unreadable payloads.
- Exit and return. The server unwraps the packet and sends the request to the real destination from its own address. The reply comes back to the server, gets encrypted, and returns through the tunnel to your device.
The parts people forget
DNS
Before your browser can open a site, it resolves the domain name to an IP address. If those lookups still go to the local network's resolver, the network learns every domain you visit even with a VPN connected — a classic DNS leak. A correctly built VPN resolves DNS inside the tunnel; ClickVPN uses its own DNS infrastructure. The leaks guide shows how to test yours.
Routing decisions
Not all traffic benefits from the tunnel equally. Printing to a LAN printer through a remote server makes no sense; neither does forcing a local map service across the world and back. This is where routing policy matters: ClickVPN's smart routing sends genuinely local traffic directly while protected traffic uses the tunnel, and split tunneling gives you per-app control.
Keeping the tunnel alive
Real networks are messy: Wi-Fi drops, phones switch to mobile data, hotel routers time out idle connections. A production VPN re-establishes the tunnel quickly and quietly — this reconnection behavior affects daily experience more than raw benchmark speed.
What the protocol layer decides
The VPN protocol defines the handshake, the encryption, and how packets are framed. It determines connection speed, battery cost on mobile, and how the traffic looks to networks that try to classify it. Modern protocols also focus on being efficient and unremarkable on the wire. Our protocol comparison covers the practical differences, including VLESS — the protocol family ClickVPN supports for manual configuration.
Where trust sits in this design
Everything between your device and the VPN server is untrusted by design — that is the point. But the VPN server itself decrypts your traffic to forward it, which means the provider's policies are part of your security model. A strict no-logs approach, minimal data retention, and infrastructure designed not to persist activity (like RAM-only services) are what make the design trustworthy end to end. See security and privacy in ClickVPN for the specifics.
FAQ
Does the VPN encrypt everything on my device?
Everything that goes to the internet while the tunnel is up, across all apps — subject to your routing settings. Traffic you exclude via split tunneling goes direct.
Can my ISP tell I am using a VPN?
It can usually see an encrypted connection to one host and its volume. It cannot see what is inside. Modern transports are designed to look unremarkable among ordinary encrypted traffic.
Why do VPNs need apps at all?
Something has to create the tunnel interface, manage keys, handle reconnects, and apply routing policy. That is the client's job — via the ClickVPN app or a compatible client with an imported profile, as described in the VLESS guide.