What is WINS?

Not satisfied with DNS, Microsoft invented another naming service for Windows, called WINS (Windows Internet Name Service). WINS is a Windows-specific name service for TCP/IP and is meant for networking geographically distant Windows computers (it typically isn’t used on a local area network). WINS not only maps names of servers but also maps names of workgroups and NT domains.
It’s unlikely that WINS will be around in the next generation of Windows machines (although it’s still around in Windows 98); Microsoft is taking a page from the competition’s automatic name services and directory services and will be rolling TCP/IP name services together with their username and password services. This will be called Active Directory.
The notion of a directory is similar to the name services concept, but it goes one step further: Instead of simply resolving a name to a number, directory services offer many pieces of vital data on the network. In particular, directory services allow users from all over to log in to the network rather than into a specific server; each server on the network relies on the directory services to assign security rights, and so on.

This is terrific because administrators no longer need to update multiple servers with username and password information; instead, they can administer updates from one point and distribute them throughout the network. Although the long-term goal has been simplification, which makes troubleshooting easier, beware of early implementations. Even Novell’s NDS—arguably the “best” directory service around (it’s been around a number of years and has a lot of support)—had a lot of problems out of the gate.
Some sort of directory service—whether it’s Microsoft’s, Novell’s, or Acme’s—is definitely in your future.