One of the key features of Chrome is that separate sites are treated as separate processes by the browser--that is, you can think of each tab or window you open as a unique application, even though they're all running in Chrome. The benefit, as a user, is that if a site crashes, it will only kill the particular window or tab that it's open in; everything else will keep right on running--you can switch to other open tabs, open windows, and do anything else you might normally do.

Treating each site as a separate task a great improvement, and is probably the single strongest reason to use Chrome over the other OS X browsers--no longer will you lose all your open tabs just because of one troublesome site.

When Chrome detects a tab has crashed, you'll get a nice pop-up window, as seen at right, to let you close the troublesome page.

The downside of treating each site as a separate process is that you can chew through memory in a hurry. As a simple test, I opened the same five sites in Chrome and Firefox 3.5, and compared the total real memory usage in Activity Monitor. Firefox used 172MB of RAM to open the five sites; Chrome required more than 275MB. If you work with a of open tabs and windows, you'll want to keep an eye on your memory usage; all the speed of Chrome isn't worth anything if you use up your RAM and start using virtual memory.