I dont understand the real difference between dedicated ip and the other one. I mean how can it help you with your blog?

Thanks.

No not really, well google can penalise you if you have a shared ip with other users that have porn sites on it ( yes lame I know some new dude came to work for google changed up anti spam policiy and such )

but if that ant case nothing really.

A dedicated IP is useful if you want to run an ecommerce site or anonymous ftp. People say having a dedicated IP will give you a search ranking boost. Im not so certain on this.