As already mentioned, Drupal is derived from the English pronunciation of the Dutch word "druppel" which stands for "drop", the name of the drop.org community. Drupal's nickname of "Community Plumbing" has a parallel etymology: the word plumbing relates to water, from there to drop.

The drop metaphor is a useful framework for thinking about Drupal and social software design. Social software depends on self-organizing networks using the packet-based, end-to-end design of the Internet. Some of the social plumbing of Drupal that facilitates networked connections between Drupal sites includes

• Drupal distributed authentication system which allows Drupal site users from one site to login to another without registration using a standard login ID: <username>@<original_site.com>.
• Implementation of Friend of a Friend (FOAF) protocols in Drupal"s FOAF module which transmits user profile information between Drupal sites.
• XML encoded Rich Site Summary (RSS)--or "Really Simple Syndication"--and RSS aggregation. Drupal provides RSS feeds for the home page, user blogs, and specific category tagged posts, among others. Additionally, Drupal includes an RSS aggregator to pull that content directly into a Drupal site. Coupled with RSS, aggregation adds the means for two-way traffic of shared content between Drupal sites.

The significance of end-to-end Internet design depends on the simplicity of the packet, a drop in the plumbing through which information flows, organizing networked virtual space into amazing things. Open source applications are often more modular than their proprietary counterparts because modularity allows developers to join in a community and extend the application much more easily. In Drupal, this recognition of simplicity for creating modularity is further represented in the node system, a database abstraction layer which is the back bone which holds together all pieces of content such as stories, polls, blog entries, and so on. In Drupal's world, such a piece of content is referred to as a "node." Often different types of content still share a number of properties such as some sort of title, an author, a creation date, body, and much more. Similarly, there is a number of operations that one wants to perform on any type of content. Example operations include adding a comments, querying access rights, categorizing content, moderating content, versioning content and so on.

The node system capitulates on these common data elements and operations. It is the node system's job to keep track of each node's elementary properties. Apart from these bookkeeping duties, the node system makes available a set of interfaces that make it possible to query and manipulate nodes. It is best to think of the node system as a conceptual "black box" that lets you couple and manage different types of content and that promotes reusing existing code, thus reducing the complexity and size of Drupal as well as improving long-term stability.