Perhaps an analogy would work best here. Lets say you forgot your bank pincode and you have to send a letter to the bank to request a new pincode. To make things worse, the bank is a foreign one and the letter has to travel all the way there.

The system for sending a letter is quite simple; you write your address to the corner and the receiver's address to the center of the envelope and then you take it to the post office.

The Journey

After taking it to the post office the letter starts its long journey during which it will carried by foot, by car, by train and even by plane or by ship. Before your letter arrives at the destination it may have visited several countries, multiple vehicles and dozens of people.

If one of those people who took part in delivering your letter had bad intentions, they could easily open up the letter, read the contents and retrieve your bank pincode. Now all the thief would have to do is to read your address from the envelope, find you and steal your bank card.

VPN To The Rescue

This is where the VPN kicks in and saves the day without you having to do anything. You buy the VPN service and carry on sending letters as normal. You even write the addresses normally to the envelopes but before taking them to the post office, you run them through this VPN encrypting machine.

The letter comes instantly from the other side of the machine and every piece of text on the letter has been encrypted. The letter and your home address is all gibberish now. It's totally unreadable. Also the receiver's address has changed, it's no longer the bank's address but the VPN office's address. You take the letter to the post office after which it will again start its long journey.

The New Journey

But this time the journey is different. Even if the letter had gone via thousands of hands no-one could tell the message. Even if they had opened it up, they couldn't tell who actually sent it. All they know it's heading to the VPN office.

When the letter arrives at the VPN office, they will decrypt the gibberish and turn it back to normal readable text. Content wise the letter and the delivery address now look normal but this time the return address has changed. The VPN office removed your home address and added theirs. The letter will now start to travel towards the bank.

When the bank receives the letter they can't say from which address it was originally sent. They only see the address of the VPN company. They write up a response and send it to the VPN office.

Upon arriving at the VPN office, the people working there run the letter through a VPN encrypting machine to turn it to gibberish again. This time the only non gibberish text is your home address so the post office can deliver it back to home where you can decrypt the gibberish back to normal text.