Tor was originally designed, implemented, and deployed as a third-generation onion routing project of the U.S. Naval Research Laboratory.Tor is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet. It also enables software developers to create new communication tools with built-in privacy features. Tor provides the foundation for a range of applications that allow organizations and individuals to share information over public networks without compromising their privacy.

Individuals use Tor to keep websites from tracking them and their family members, or to connect to news sites, instant messaging services, or the like when these are blocked by their local Internet providers. Tor's hidden services let users publish web sites and other services without needing to reveal the location of the site. Individuals also use Tor for socially sensitive communication: chat rooms and web forums.

WHY do we need tor?
in today's digital world identity is everything. government agencies such as NSA and almost the entire chinese government and many others have a hobby of analysing the traffic in their respective countries and have the access to all your browsing history. this is an invasion of privacy and might reveal sensitive information about you. TOR is the answer to all these things it helps you stay annoymous.
+you can also access DEEP WEB using TOR!

for more info visit: https://www.torproject.org/

I am really concern about the recent news. https://blog.torproject.org/blog/tor...rmation-attack.

On July 4 2014 we found a group of relays that we assume were trying to deanonymize users. They appear to have been targeting people who operate or access Tor hidden services. The attack involved modifying Tor protocol headers to do traffic confirmation attacks.

@Maddie nothing is permanent but change.You might be secure now but who knows about tomorrow!
This anonymizing and de-anonymizing is like a game it's never sure that you'll win(remain anonymous) but tor gives you the best odds compared to any other free method.
As far as the above mentioned incident is concerned it was not a target specific attack , they were jst trying to deanonymize some users but they had no idea what and who were they trying to track so its all ok now!

You can always use TOR over a VPN connection for extra security, connect to VPN then use TOR.