Simple wp directory query (I hope)

Hi,
please forgive my general ignorance, but I was just wondering whereabouts in the wordpress directory text data is stored? So when I create a new blog post, write out a load of text, where exactly is that text data saved in the directory and how can I access it?

Long story short, my blogsite suffered a massive balls up which has left me having to reinstall wordpress, I’ve got a copy of my old wordpress directory folder before it messed up so I’m assuming all my post information is hidden in there somewhere, i just dont know where…

Hope some one of you fine, knowledgeable people can help.

Cheers