what kind of site are you trying to make?
some sites you can do in just a few pages, some you will need a few more pages, which is where you rewrite mod comes into play to clean up the urls for SEO
Google doesn't really score any higher for clean urls, it is just for the user, when they see your web url in amongst the other results in google they will see a clean legible url and not just numbers such as "/index.php?productid=124344" instead in google they will see "/index.php/samsunglaptop-model-nc10" which is what you are trying to achieve?
and it is also helpful as some users who type into their urls such as the word NC10 your site will popup in their previous history....
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