What is Trackbacks, Pingbacks in Wordpress?

[hoangvu]

Hi everyone,

I don't really understand the trackback and pingback function in WordPress blog. Sometimes, I got emails notice about that
however I don't know which benefits when we turn on or off these functions? and what do they use for?
can you give me a little about Trackbacks, Pingbacks in Wordpress, how does it effect ranking ?

thanks in advanced!