A majority of our clients are small businesses. most of those do not have a server. OK terminology they have a workstation that is sharing files and that is what they call a server. But does this really work and how can it be better. To answer this one has to understand workgroup computing. Yes there exists a machine in a workgroup or multiples that serve files. If the file is changed by another user on another computer everything works. THe same with printing. The issue is that a user can create a file on their system in their My Documents directory that is only available to them and may never get backed up. File sharing becomes interesting as user change their password on their local machine as the network share will then deny them access. This is because in a workgroup environment user identical user accounts must be set up on each machine or you must disallow all security. So we now have two issues security and backup. One of the easiest solutions to this problem is Microsoft's Small Business Server line of products. It solves the user security issue by creating all user accounts in one place and those accounts work on every computer. With My Documents redirection, everyone's My Document folders are synced back to the server, which gives a single backup point. Plus if you go to another workstation your My Documents folder from your other computer is accessible to you. More important is now all the critical files can be backed up from one place.
Of course Microsoft SBS has a ton more features which include Sharepoint services for collabrative work, Exchange Mail Server, Windows Server Update Services (to ensure all the systems have the current security patches), Remote access to your network and desktops. You can even do your own web site. There is a lot more behind SBS than these items, but for most Small Businesses, print and file sharing and disaster recovery are critical and not really addressed in Workgroup computing.