What's the Difference Between A Brazilian Blowout and a Straight Perm?

I have medium-thick asian hair.its half way down my back. It is all straight except this one part below my neck where it poofs out then is straight again. Its wavy i guess. I might get it straghit but whats the diff between a brazilian blowout and a straight perm? Is it safe, will it kill my hair, etc. Thankssss(: and the costt.