Microsoft Knowledge Base Article 323967 contains the following summary:
Windows 2000 supports two different types of drive assignments. A new drive (or a partition on that drive) is either typically assigned a new, unique drive letter (for example, drive C is used for the startup drive). Alternatively, you can assign a mount point for a drive or a partition in the same way you do if you use UNIX. You can use the path format to easily split up the content of a Web site across multiple drives without using redirection or virtual Web site directories. This article describes how to configure a new disk drive, create partitions, and assign a drive letter or a path to the partitions that you create.