Maps
Maps is an add-on available to all users that allows you display a Yahoo! map on your web site. When you set up Maps, you enter a destination address and create a "Show Map" button; your site visitors can click this button to locate the address you specified on a map. You can use Maps to provide a personalized way for your visitors to locate your business or other destination. Learn more about add-ons.
megabyte
A megabyte equals about 1,000 kilobytes (actually, 1,024KB), and approximately 1,000,000 bytes. A byte is the smallest unit of data measurement in computers. The following conversions will give you an idea of how big a megabyte is:
1,000 bytes (B) = 1 kilobyte (KB)
1,000 kilobytes (KB) = 1 megabyte (MB)
1,000 megabytes (MB) = 1 gigabyte (GB)
Yahoo! GeoCities measures disk space and data transfer in megabytes.
moblog
Moblog, which derives from the words mobile and blog, refers to blog content posted from a mobile device such as a cellular phone or PDA. You can use moblogging to post to a Yahoo! 360° blog.
module
Tools and features on the tabs of your GeoCities Control Panel are grouped thematically into smaller sections called modules. The Create & Update tab, for example, includes modules that group basic site building tools, file management tools, and learning resources. Next to the titles of the main modules (except on the Index tab), you'll find a small arrow, which you can use to collapse or expand the module (make it smaller or bigger). Click the arrow once to collapse a module you rarely use, minimizing the space it occupies on your control panel; when you're ready to use those features, click the arrow again to expand the module. Learn more.

Modules on the Home tab
MySQL
MySQL, considered the most popular open-source database in the world, is a powerful, reliable tool used to quickly access stored data. Experienced users can also use MySQL to create dynamic pages and site elements of their own. Learn more.