DRY is a bit of a mantra with developers. It means Don't Repeat Yourself.
It should be a mantra for content owners & creators too. From a developer point of view it makes code much more manageable and maintainable. The same applies to building your site and most CMSs offer some sort of 'Token' system so that you can create blocks of regularly used content and then drop them in wherever you need them. Drupal offers a number of ways to create content once and then use it wherever you need it.
Two good examples of content reuse would be your company phone number, another would be a standard disclaimer that you apply to your services or products. You could copy and paste your disclaimer into the content of every page you want it on, but there are two big problems with that. The first is that it's a waste of your time and is really quite boring, the second is that when you add a new clause to your disclaimer or reword it you have to edit every single page it appears on. And you'd better not miss any, or your lawyer won't be very happy with you. What if, instead, you could type something like '[site:disclaimer]' into the content, or select it from a drop down, or select a checkbox and have it appear where you needed it. One place to update, one easy way to use it wherever you need - no copy and paste, no tracking down which of the multiple versions now on your site is the correct one.
DRY is something we keep pretty close to our hearts - and it flows through the way we design your site and the interface that you use. If you need a piece of information in lots of places then we just store it once and then everything else points to it. Very useful in an earthquake zone when you need to update your address, your phone number and your opening hours - edit once and your whole site is up to date.
If you're spending time doing repetitive work on your current site then talk to us about how we can save you time, make your site more professional and let you spend time on the aspects of your business that really drive it forward.
PS The opposite of DRY is, of course, WET - Write Everything Twice!