VPN

VPN is Vitural Private Network which can trespass local connection and unblock blocked websites such as Facebook, YouTube and some page as well. They usually blocked websites at schools, college and university, even in China, where China have the biggest economy growth (this doesn't apply to Hong Kong, Macau and Shanghai free trade zone). Plus, they private your network from anyone else (like government) which website you're going.

Here's the pros and cons about VPN.

Pros

 * Trespass blocked websites
 * Hide from government which website you want to access
 * Secure
 * Many server to choose from

Cons

 * Slow if you choose unstable server
 * Some countries like China blocked some VPN server