Tor Browser is a toolset that's designed for anyone who wants to improve their safety and security on the Internet. It can help you anonymize web browsing and publishing, instant messaging, and other applications that use the TCP protocol. For business users, it means that confidential exchanges of information can be kept from prying eyes and for more general users, it means that ISPs, keyloggers and other types of malware can't track your activities easily.
It works by bouncing traffic around a distributed network of servers which it calls "onion routers" (hence the logo). The Tor Browser interface allows you to easily toggle it on and off based on when you need to go online anonymously - there's no need to restart your computer when you've done so. If you want, you can also choose from various proxy tunnels based on a world map which displays exactly where each one is located.