Fetch data from Google Spreadsheet

how can I fetch data from a google spreadsheet? It's not something like embedding a google doc on a webpage. Suppose, you have a table consisting of 10 rows and 10 columns at google doc. Now, you created a 10x10 table on a PHP webpage. Now you will show the respective values of the cells from that google doc to your php page. It's just like fetching data from a MySQL database and showing them on your web page. But here instead of using a MySQL database, I want to use Google Doc and do the rest. But how can I do it? Thank you.