MS Word 2007 retains almost all MS Word 2003 features and presents them in a different, easily accessible manner. It also employs use of contextual menus. These menus are operation specific and do not appear until you are on a job such as using tables or pictures. This means there is no separate Table menu in Office 2007. If you are using a table, you will find contextual commands at your hand such as inserting rows and columns and formatting the table. Similarly, formatting features for an image will appear only when you are working on an image in the document.
MS Word 2007 includes some enhanced features related to sharing and publishing documents directly from the application interface. The Office button at the top left corner allows you to access these commands. You can publish your document directly to your blog, or you can email them. If you wish to share a document for research or discussion, you can again use the Office button to expand the menu where the commands are located.
If anything has really changed between MS Word 2003 and MS Word 2007, it is the application’s interface. Though it looks unfamiliar, this interface (called the Ribbon) is more convenient to use as it presents commands neatly in an uncluttered fashion. The tabs on the Ribbon interface convey what all you can expect to find under it. For instance, if you see the Insert tab, you’ll know that it is meant for adding/inserting something to your document. The Review tab conveys that you can get features for document review under the tab. These include tracking changes, comments, and comparing documents.
In short, both versions carry almost the same features. It is just that MS Word 2007 presents them in a different manner, offering a cleaner layout for quicker access of commands.