Answer:
The two do not use the same exact formats, but it's very quick and easy to make them work together. If you have a document already saved on Google Docs, go to your Docs home page, click on the file you want to open in Office, then at the top go to File>Download as>Word/Excel/PowerPoint, etc. This will give you a the correct file format for Office. And if you have a Microsoft Office file that you want to import into Google Docs, look for the "upload" button next to "create" on the home page, then select your Office files. Google Docs will automatically convert the formats for you if it's in the original Office formats (e.i. .doc, .xls, .ppt, etc.).