301 and 302 Redirects: What's the difference?

Chances are you have come across a 301 redirect at some point on the web, but maybe also a 302 redirect... but what's the difference between the two and whys is that important? Bruce Clay gives the answer in this Ask Us Anything video!

Here's the full question: "My domain name is very easy to misspell, so for that reason I have purchased common misspelled versions of my domain name and have them all redirect back to my main site. I'm not a SEO expert, but 301 and 302 redirects both seem to do the same thing, so I ask: Why is a 301 redirect preferred over a 302 redirect if both seemingly do the same thing?"