By way of metaphor: When you hand your friend a letter and ask them to mail it from their mailbox, that friend acts as a forward proxy. The post office doesn't

By way of metaphor: When you hand your friend a letter and ask them to mail it from their mailbox, that friend acts as a forward proxy. The post office doesn't know from whom the letter originates, only that the friend sent it. When you go to the post office and hand the clerk your letter, that clerk acts as a reverse proxy. You don't know what happens to the letter from that point on. Common cases: Say your friend provides this service for your entire town, then they're acting as a privacy VPN (since now the post office can only say a particular letter is from the town). Say you want to send a letter to that celebrity but the celebrity's security team will toss any envelope not on the approved list. So you ask your friend, who is on that list, to put your letter in their envelope so it'll get through. Now your friend is acting as an access VPN.