Phoenix: Effective Web design is driven by the need to balance flexibility and simplicity. If a system is too simple, it can only be used for a single purpose - but if it is too flexible, it may be too difficult for new users to learn.
Drupal strives to reconcile these conflicting goals by providing its users with the tools they need to make their own content management solution, while still providing some pre-built components to help them get started. Thus, it can be described both as a content management system (CMS) and a content management framework (CMF) - one system which strives to have the strengths of both, without their deficiencies.
Most CMS's are like a toy boat or truck - specific assumptions have been made about their use, assumptions that would be hard for you to override. Frameworks, on the other hand, provide you with raw materials only - you need to know a programming language and have a clear design vision to put them together.
Drupal is like a Lego kit. Skilled developers have already made the building blocks - in the form of contributed modules - that you need to create a site that suits your needs, whether that is a news site, an online store, a social network, blog, wiki, or something else altogether.
Drupal in action
To make the contrast between Drupal and other CMS's more concrete, consider the example of a news site. You want to be able to post news articles on the site, and you want the homepage to have a section featuring the five most recent ones. Next, you decide that you want to add a blog section, and put a list of links to the five most recent of blog entries on the homepage as well.
If you were using an ordinary CMS, first you would install a plug-in that handled news articles and could put short blurbs on the homepage. Next, you’d install a plug-in that would track the latest blog posts and put a list of those on the homepage. Each plug-in would only be responsible for tracking and managing a particular kind of content, and would remain relatively isolated from the others.
But, what happens when you have that brilliant middle-of-the-night idea, and want to blend these two functions by showing a list of blog posts about the latest news items, ordered by most active contributor first? If you’re using a “toy truck” CMS, you may be out of luck, or need to hire a developer to write you a custom plug-in from scratch. But through the power of the Drupal the way of manageable abstraction you can whip out a kit full of parts and knock this together pretty quickly. (Hint: just use Views.) Since Drupal's modules do things in a standard way, and interface with a common underlying system, building all sorts of clever, customized features is just a matter of snapping parts together.
Of course, this flexibility comes at a certain cost. While a toy truck is instantly understandable and ready to use without much thought, a modular vehicle construction kit will by nature require you to read the instruction manual first. The building blocks are out there, but you'll need to learn how they fit together before you can take a paper prototype and turn it into a full-featured website.
Drupal core, and the thousands of contributed modules that build on it, require an initial investment to learn, but mastering the Drupal way is immensely rewarding; the passionate community is a testament to its power to liberate site builders from the simplicity/flexibility dilemma. Once you've tried Drupal, you'll likely leave your toy truck and boat in the closet gathering dust.