While many of us may not be able to define the word “taxonomy,” the reality is that we use taxonomy on a daily basis as a means for categorizing “things” in our lives. If you open the doors to your kitchen pantry, you might find an orderly assemblage of food items: all of your spices on the top shelf, canned food on the second shelf, pastas and other boxed foods on the third shelf, and cereal boxes on the fourth. Categorizing your food items and putting things away in an orderly fashion so that you can easily find food items when you need them to prepare a meal is in its simplest form the use of taxonomy. Without this “kitchen taxonomy system,” you may have everything you need to make dinner jammed randomly in the pantry, but finding it may be a challenge, leading to frustration and a phone call to the local pizza delivery restaurant when you’re not able to find the ingredients you need to make a meal.
In Drupal, taxonomy is divided into two general capabilities: tagging and structured taxonomy. Both are powerful solutions and can be used simultaneously on your site. Tagging is a simplified yet powerful use of the taxonomy system, enabling content authors to enter keywords that describe the content in a text field on the content editing form. As an example of tagging content, an author who writes an article about alternative energy could use keywords, or tags, such as “solar,” “wind,” and “geothermal” to categorize the article. The keywords created by the author are typically displayed as hyperlinks at the end of the article and can be used by site visitors to locate other content tagged with the same keywords. All Drupal developers are aware of the power of taxonomy.
Tagging is freeform, meaning it’s up to the author to define what words they want to use to classify their content. A common issue with using tagging as an approach to categorize content is that different people use different words to refer to the same concept. For example, an article about rain might be tagged with the word “rain” by one author, “precipitation” by another author, and “drizzle” by a third. Site visitors trying to find articles about the general concept of rain would have a difficult time finding the ones tagged with words other than “rain.” Another common problem is misspellings. If an author tags an article about rain with “reign,” then site visitors are going to have a hard time, using taxonomy, to find that article using the word “rain.”