Originally Posted by: blowupman... i wanna know what exactly is a breakdown ...
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http://en.wikipedia.org/wiki/Break_(music)

Typically this refers to "breaking down" the elements or components of a song to a minimum. That's why when you hear, "Break it down!", you hear many (or all) of the instruments stop playing while the drums keep a constant rhythm going.
[QUOTE=blowupman]
i know it has something to do with halving the tempo/beat on the drums