what's the point of do-follow, no-follow, and the importance of each?

is there any real benefit of using do follow or no follow other than keeping others from grabbing your stuff for a feed/posting on their blogs? Can someone please break it down simply, and especially why it's important to do (whichever) for your blogs, sites, etc?

thanks

 

You shold use the no-follow tag to tell the spiders not to crawl a link. Google implemented this tag to combat spamers who abuse blog commenting. Dofollow is just not using no-follow tag.

 

ok, but how does no-follow really help because spammers will still spam? thanks again

 

Who you link to can harm your own reputation. Nofollow will preserve your reputation.

Read up on nofollow here.

 

I think spammer will not stop try to filter it manually,...No-follow link is not useful to Google but not in other search engine like ask,aol etc.

 

Commenting on dofollow blogs will not just provide you with traffic but also PR juice...

 

dofollow blogs with good rank is good way to improve your site and maybe drive some traffic too