Choosing between the peer-to-peer and client-server network architectures can be daunting in light of the ups and downs of each type. Perhaps the following simple rules of thumb may provide some help:
A peer-to-peer network is often a reasonable choice in a home network, or other environment where significant growth in numbers of users or quantity of computer-based work is not expected, where security is not a serious concern, and where there is little or no need for major system-wide services.
The client-server architecture is usually the correct choice, even in a small business, where growth is anticipated, security matters, and sophisticated server-based services will be beneficial to productivity.
Well, why not start off with a peer-to-peer network architecture and then move up to client-server when the time comes? Because, unless there is some overwhelming consideration to the contrary, it is likely more cost-effective and productivity-effective to begin with client-server, despite the initial cost difference.
Home Network: An interconnection of computers in a home or other non-business environment, providing for basic levels of resource sharing without significant concern for security.
System-wide Service: A network-available resource which provides a benefit or particular service to an entire organization. Examples: email and fax service, database hosting, company intranet, company calendar.
Small Business: This one is tough to define, since in network capacity planning an organization with 500 or more employees is often treated as 'small.' However, for our purposes here, we'll define a small business as one requiring 50 or less connections to a server at a time, because that's the number permitted under Microsoft's BackOffice Small Business Server 4.5, a complete suite of networking services (just like the big outfits use) and available at a very reasonable cost.