WordPress permalinks and SEO – what does google read?

Hello all,

If through out my whole website, I have all my hard coded links (anything I’ve typed in myself) to have the page id on the end (default permalink), but have custom url structure, does google read the custom url structure or the default permalink?

so, as example.

I have a page the the url:
http://www.website.com/website-long-tail-url

but throughout the website (pages, posts, .php files, ect.) it is coded like this:
http://www.website.com/?page_id=1

will google read this:
http://www.website.com/website-long-tail-url

or this:
http://www.website.com/?page_id=1

I hope this makes sense.