This feature is extremely useful for your SEO.
When you first create your database, the database name is used as a page title.
The database name should be short, as it is used in many places in your community, for example in activity streams, notifications or +Create Menu. At the same time, you might want to use a kind of slogan instead of the database name on the start page.
In database settings in your AdminCP, you can choose to use page title instead.
The page title is set in the page settings:
Unfortunately, if you use a default articles template provided from Invision Community, this setting will be ignored. At least for the databases that use categories.
FX Pages corrects this glitch and respects the setting for each database. See the result:
Page title is one of the most important mark-ups for SEO. Use this feature with the keywords wisely. Put a nice slogan on the start page instead of database name, explaining a user what this area is for.