What is the difference between using Google Safe Browsing and using other traditional anti-webmalware tools ? Which one is more efficient to protect against malicious web content ?
"Google Safe Browsing" is mostly a large directory of Web sites which appear to contain malware. When you use Safe Browsing, your client is talking to the Google's dedicated server, with a question like this:
— Tell me, mighty Google; I am about to visit
evilhackerzfrompatagonia.com. Is that safe ?
To which Google will respond either:
— Do not fear, friend browser. I went to that site myself yesterday, and nothing on it appeared amiss at that time.
— Stay your network packets ! That site is a malware-infested hellish server; or at least so it was when I last had a look. Steer away from it !
So that service is really relative to what Google's systems so when they last visited the same site. However, a site owner may detect whether a given visitor is an actual human, or Google's automated services; therefore, an evil site owner may elect to show a collection of pictures of cute kitten to Google, while sending malware to everybody else. Google Safe Browsing would be none the wiser.
Other anti-malware tool inspect what you actually download. They don't prevent the fateful connection, but they see exactly what is entering your computer, and they sit sufficiently early in the input data flow that they may prevent incoming malware from harming your computer, if they detect it as such.
Such tools are in a better position to make an accurate diagnostic of the malwareness of incoming data, since they work, by definition, on that exact incoming data, and not on what was sent to another system the day before. In that sense, they seem "more secure". On the other hand, all the detection must be performed by your computer, which may not necessarily have a lot of available computing power for the job. More importantly, Google's systems have a worldwide view and thus a lot of data to cross-correlate with.
So the answer is mixed: though Google Safe Browsing is easier to fool by sending it innocent harmless files, it is also much better at deciding whether a given file is malware or not. So the two kind of services are really complementary. You don't have to choose between Google Safe Browsing, and a local anti-malware tool; just use both !