In this iteration of Office software, Microsoft has introduced the Office Starter 2010, to replace Microsoft Works. This edition includes Word Starter 2010 and Excel Starter 2010 only.

This is a free but ad-supported version of Microsoft Office 2010.

Office Starter 2010 will come pre-installed on an OEM PC, as a part of the PC Essentials, and is designed for home users who are not ready to buy a full version of Office 2010.

This will be thus available through PC manufacturers and system builders on new PCs, where it has been pre-installed via a Single Image. However, customers can easily switch to a full version of any one of the three Office 2010 products.

This version should suffice for most home users as they in any case primarily use Word & Excel only!

These links may interest you:
Can you download Microsoft Office 2010 Starter Edition?
What can Microsoft Office 2010 Starter Edition can and cannot do?
Licensing Terms for Microsoft Office Starter 2010.