Add keywords vs. categories to user docs

CHANGELOG.md

@@ -10,6 +10,9 @@
 - Usage of caches for NPM speedup
  [#883](https://github.com/nextcloud/cookbook/pull/883) @christianlupus
 
+### Documentation
+- Added clarification between categories and keywords for users
+ [#889](https://github.com/nextcloud/cookbook/pull/889) @MarcelRobitaille
 
 ## 0.9.9 - 2022-01-13
 

docs/user/index.md

@@ -5,7 +5,7 @@
 
 ### Importing from a Website
 
-Recipes can be imported by entering the URL to a recipe in the text-input field in the top right area of the Cookbook app. 
+Recipes can be imported by entering the URL to a recipe in the text-input field in the top right area of the Cookbook app.
 
 <img src="assets/create_import.png" alt="Recipe-import field" width="200px" />
 
@@ -23,4 +23,25 @@ Currently, the only way to share recipes is by sharing the Nextcloud folder that
 
 ### Public Sharing
 
-At the moment it is not possible to share a public link to a recipe.
+At the moment it is not possible to share a public link to a recipe.
+
+## FAQ
+
+### When should I use keywords and when should I use categories to organize my recipes?
+
+The use of keywords and categories is entirely up to you.
+
+The primary difference between the two is that a recipe can only have a single category,
+but may have many keywords.
+In other words,
+categories are a 1:N relationship while keywords are an N:M relationship.
+
+Categories can be accessed more directly than keywords,
+as they appear in the sidebar.
+By clicking a category in the sidebar,
+you can quickly narrow down recipes to a certain class, like "Main dishes" or "Deserts".
+Then, keywords can be used to further narrow down the selection
+with tags like "vegetarian" or "easy".
+In this way, categories are used for rough filtering and keywords are used for fine filtering.
+
+![Example workflow using categories for rough filtering and keywords for fine filtering](assets/keywords-and-categories.png)