Regarding Tor, I use it at times. I see that they use DuckDuckGo. Is using Tor a double protection or why not just use DuckDuckGo by itself? And what is onion routing? Something like a VPN?
In reverse order:
- This Wikipedia article describes the details of Onion Routing: but in practice it is a technique of sending every communication through at least three remote servers located in countries other than the contry of origin with point to point encryption between each server as well as end to end encryption. Think of Onion Routing as a VPN on steroids to the point it is used by the NSA, USAF, USN, State Department, FBI, and a host of other super secure government agencies.
- This Wikipedia article does a good job of explaining DuckDuckGo and how it differs from Google et. al. I have changed the setting in all my browsers to make DuckDuckGo the default search engine. I have come to prefer DuckDuckGo's search results to Google often listing excellent resources on the first search page that would be so deeply buried in a Google query I would be very unlikely to ever see.
If you will pardon a homely analogy, the TOR router, Onion Routing, and DuckDuckGo are like a three legged milking stool. Each supports your
privacy 
in a different direction and if you take any one away the stool is almost impossible to keep fully upright.
