Unified messaging is a computer-based messaging system that allows users to manage all their messages -- email and faxes as well as voice mail -- via a single inbox.

Your service will provide you with a phone number and an email address, you can use a web-based service or a traditional software-based system that is installed on your company's server.

Web-based
With Web-based products, users are provided with a single phone number where both faxes and voice messages can be sent. Users retrieve their messages using their regular e-mail, by phone, or through the Web.

If you've got a staff of road warriors, these services can be particularly attractive because they can be accessed from any Web browser.

Software-based
A software-based unified messaging system stores incoming voice messages and faxes (that arrive via the user's personal phone line) on the computer where the software is running. Messages can be accessed via phone or email as with web-based messaging - but not through the web.

If your business stays put, this is a good option. You can access your info from your PC without having to jump on the web and log on to a password-protected site.

But the same idea lies behind all unified messaging systems: all of your incoming messages are conveniently stored in one inbox, which you can retrieve via the phone, your PC, or your Web browser, depending on your system or service.