Mirrors are the way of proxying content that hosts on other domain addresses. Let's say you want to search for something in Google, but your government blocks it. You then go to a mirror which servers are in the country where this website is not blocked and type your search request there, so the mirror is now sending requests through its server and then shows content to you as you did it yourself in another country.
Let's say you live in the United States and Thepiratebay is blocked here, but your friend John lives in Portugal, where it is not blocked. You call John and ask to find a new game and send it to you. He then goes on the website, downloads a torrent file, and uploads it for you. You are thankful to John for it.
But our mirrors are an automatic robot that is now doing the same thing your friend John would do without any calls or wasting your time. Open our platform, choose a mirror, open it, and that's it - you bypassed your ISP's ban.