Try going to that link if you don't have an Office Live account.

You
won't find out anything at all, other than the fact that you're an
unrecognized user.
After Googling and trying a variety of different links matching "what is
office live"--none of which answered the question--I finally gave up and
tried the old fasioned way... WikiPedia:
http://en.wikipedia.org/wiki/Office_Live
Even so, it's still written in Microsoft-ese, which makes it hard to see why
it's called "Office Live" or how it differs, say, from an infinite number of
similar offerings from a variety of different companies (Google, Yahoo,
etc.).
This press release tells a bit about what the different levels of OL are:
http://www.microsoft.com/presspass/press/2006/feb06/02-15OfficeLiveBetaPR.mspx
It boils down to:
• Microsoft Office Live Basics. A collection of free services
(advertising-supported) will provide a small business with the core
requirements for establishing an online identity. Services include a company
domain name; five e-mail accounts using that company domain name, each with
2 GB of storage; a Web site with 30 MB of file storage space; an
easy-to-use, drag-and-drop design tool for creating a compelling,
professional-quality Web site; and the Microsoft Office Live Site Reports
tool for monitoring and analyzing Web site traffic.
• Microsoft Office Live Collaboration. Designed for small businesses that
may already have a Web site, this subscription offering provides a rich,
versatile set of Internet-based business management tools that are managed
and maintained by Microsoft. Based on Microsoft Windows® SharePoint®
Services technology, the Microsoft Office Live Collaboration service offers
small businesses password-protected online workspaces (intranets and
extranets). Capabilities include customer management, project management,
sales and marketing management, employee management, and company
administration, as well as password-protected internal shared sites to
facilitate collaboration among employees, customers, suppliers and other
business partners.
• Microsoft Office Live Essentials. A comprehensive set of business
services, this subscription offering will provide customers with the
resources and collaboration tools they need to establish and manage a small
business online. Services include a company domain name; 50 e-mail accounts
using that company domain name, each with 2 GB of storage; a Web site with
50 MB of file storage space; the same Web design tool as Microsoft Office
Live Basics, plus Microsoft Office FrontPage® support for advanced Web
design; more advanced Web site analytics; and a rich set of Internet-based
applications to help small-business owners streamline and automate daily
business tasks, such as management of customers, projects and documents.
If the name makes you think that Office Live is an online/web-based version
of Office... you're wrong (like I was).