• servername and description
• browser title, site slogan, description/keywords meta tags, start page
• a dedicated theme
• the language
• header, column, and menu details

Use it to

• characterize: use www.bitweaver.org, doc.bitweaver.org and dev.bitweaver.org for different aspects of a project
• localize: use en.mysite, en-uk.mysite and uk.mysite to serve different languages to your visitors
• seperate: band-1-fans.com and band-2-fans.com - one database for 2 different fan sites

Advantages

• only one database - users feel they are in a different section while it's still using the same database
• easy maintenance - one install, one upgrade, combined pages (repeat content on all multisites), combine newsletters/shoutbox/search ... and so on
• visually effective - different sections of your site can sport a different theme (plus you can still use different themes for each package of each multisite)
• restrict access to content on a site by site basis so that only a subset of the content is seen on any given site (available in Bitweaver 2)

Notes

• Multisites is not intended for setting up entirely independend sites with different databases. All URLs access the same database.
• In all versions below Bitweaver 2 you can not restrict access to content on a site by site basis.