What Is a Drupal Distribution?
Then someone tells you about OpenPublish, a hot new CMS that sounds like it fits your use case. Somehow, OpenPublish is mysteriously "powered by Drupal". Or was it called OpenPublic? Or OpenScholar? Then someone else in your office hears about "Pressflow." Pressflow is also Drupal, only better ... somehow ... oh, hey, how about that Managing News ... wow, powered by Drupal!
Welcome to the world of Drupal distributions. Don't be overwhelmed. Once we cut through the confusion, you'll see that a Drupal distribution could make your next website astoundingly easy.
A Drupal Distribution Is Still Drupal
Here's the secret: they're all just Drupal.
Remember, you can basically boil down any Drupal web site to a few parts:
Core Drupal: This basic program runs the whole show, and is the same (or should be) on any site which is running that version of Drupal. The White House and the Economist have very different sites, but if they're both running on Drupal 7, they're both running (basically) the same core code.
Modules and themes: Here is where web sites become wildly different. Different sites need to do different things. A lot can be done with core Drupal, but almost any site will need modules (sometimes many) to accomplish various tasks. Themes are another obvious need, so the whole planet doesn't use the same default theme.
Configuration: Some modules work "out of the box". Download it, enable it, and it does what you want. Usually, though, you need to do some clicking and typing. This configuration gets saved in the database, or (if you're smart) in extra code.
Lastly, of course, there's the minor detail of the actual content.
So how do OpenPublish or Managing News or the hundreds of other Drupal distributions fit into all this?
Drupal Site Building Is Largely Choosing And Configuring Modules
Look again at those four parts. When you hire a developer to build you a web site, the core part is easy. He just downloads core from drupal.org, or, even better, adds a new site with a few clicks, using Aegir or some other tool. Behold: a functioning Drupal site.
(Aren't you glad you're not paying tens of thousands to build a "custom CMS" from scratch?)
Then there's the content. That part will be your job.
So all the "web development" work happens in the middle: choosing and configuring modules, and building a theme. (You may also need to fund custom module development, but that's a whole other story.)
How Is Your Site Unique?
Now, yes, you want your site to be unique. Of course. But let's face it: most of that uniqueness will hopefully be in your content. Right? Yes, your theme will need a few special touches. But basically, your site will probably function in much the same way as other sites that have similar goals.
If you run an online magazine, your site will do most of the same things that other magazine sites do. If you run an advocacy site, it will do most of the same things that other advocacy sites do. And so on.
Each "type" of site requires a particular collection of modules, with particular configurations. Often, the theme will have particular requirements as well -- you probably want your news site to have at least one sidebar.
So if your online magazine will need roughly the same set of modules and configuration as other magazine sites, why not just copy how they've done it?
Enter Drupal distributions.
Drupal Distribution: A Particular Set of Modules, Themes, and Configuration
A Drupal "distribution" is simply a particular combination of Drupal core with certain modules, themes, and configuration.
Basically, someone has built and configured a Drupal site for a particular purpose. Then, they've saved all their work, so you can copy it, and reuse it for your own Drupal site.
Why Are There So Many Distributions?
Many Drupal distributions are available, with more coming all the time. Why? Because Drupal, with its ecosystem of thousands of modules, is incredibly versatile. Every distribution is a new way to make a particular kind of site.
Get Your Distribution and Start Adding Content
The goal, in general, is for you to install the distribution and leap right into adding your content.
With OpenPublish, you can start posting news articles. With OpenScholar, you can start adding professor pages. With Commons, you can add "wikis, calendars, groups, and other social features". You get the idea.
If you find a distribution that matches your needs, you can do amazing things very quickly.
Of course, Drupal distributions aren't always the solution, and they may have some downsides. But they're worth a good look.
What About Installation Profiles?
Sometimes you'll see references to installation profiles. You can think of installation profiles as "recipes". You use the "recipe" of the installation profile to build the "dish" of the actual, functioning distribution.
Learn More About Drupal Distributions
Drupal.org includes a whole section of the online handbook dedicated to distributions. The huge list of articles about distributions looks especially intriguing (or daunting).
Or, you can skip straight to browsing the distributions themselves. Happy hunting!