You are always being told what to do while in school. Parents and school staff members are saying what you must learn, which friends you must go out with, what you ought to wear, and even what you must eat. It's a long list. You'd think you're in a correctional building or something. You would guess that after forcing you to go there and all that stuff, they'd at least let you visit any websites you like to when you're there. But, no. The internet is censored, and many sites are blocked. Luckily, there are many ways of getting around the internet filter at least, and it's a good deal more easy than convincing your parents to homeschool you.
Unblockers are like a gateway that pass information between your computer and the site you want to go to. The unblocker accesses the site you want on your behalf, downloads the page, and sends it on to you. So the site you're trying to visit never sees your IP. So, basically you are browsing websites in an indirect manner. Internet filters only think you are visiting the unblocker, not the destination site.
Another method to unblock Facebook in school is by making your own unblocker site. This is more complicated than using an unblocker but better in the long run because you can make more of them. Explaining how to do this is beyond the scope of this article, but if you search for "How to make your own proxy" you should find help. You can even earn money from letting people use it by letting people advertise on it.
Other ways to get on Facebook include by using translator sites, such as Google Translate or Babelfish. Also try Google's cached version of the site. Unfortunately, it's not possible to log in that way, so you're better off using an unblocker for Facebook, however these tricks work with most websites.