One Database or More

A bit of advice needed, as I'm having trouble figuring out whether I need to create multiple SQL Server databases or just one...or if it is a matter of choice.

Say I'm creating Website A that does one thing.

And Website B that does another thing.

But each one has common core underlying tables (customers, cargos, ports, etc) that they both use.

Am I best just creating one database or several? Then am I best creating two or three (A,B and core tables)?

Not that used to SQL server at the moment, and this will be a complete backend for the companies main core business, crm, quality, etc - all distinct apps so to speak, but the data has common underlying tables and they will want to cross-reference data.::Am I best just creating one database or several?

This absolutly and 100% depends on whether you want them or not.

In this case:

::Not that used to SQL server at the moment, and this will be a complete backend for the
::companies main core business, crm, quality, etc - all distinct apps so to speak,

No, these are NOT distinct apps. They are all parts of one suite running the company. In this case it is absolutly best to run all this:

* From one database
* with ONE SET OF BUSINESS OBJECTS.|||Yes - part of one suite. Thanks.