## Create a category dynamically
Finally, they click **Regenerate** to populate the Category with the matching Products, then rebuild the product search index so the category and products appear on the website.
Dynamic Categories use rules to determine if products are or are not displayed on its category page. The Rules Engine cycles through of a set of rules and statements resolving as either True or False, then returns the appropriate values to the Dynamic Category.
## Use case: Dynamic category for items $20 and under
Hero Tools offers many different types of products, from circular saws and grinders to spare parts. To help their users find deals, they want to create a category to list all products priced at $20 or less.
They create a category in the Admin Console called "$20 or Less." Then, they make it a Dynamic Category by accessing the Category’s **Products** finger tab and toggling the **Use Dynamic Rules** toggle to **YES**.
At the top of the screen, they choose to match **All** of the following rules, because this use case only requires one rule to accomplish the objective.
The new rule finds all products priced at $20 or less. To create this rule, they choose **Product Fields** as the Rule Type. Then, they select **Basic List Price** as the Source Data Field. They select Based On **Range**, enter **0** as the Minimum Value, and **20** as the Maximum Value.
These steps show how to create and implement a new dynamic category.
Go to **Admin Console** \> **Catalog** \> **Categories**.
Using the **Website selector** menu, in the Category list toolbar, select the targeted Website.
Click **Add New Category** to create a new Category.
Add a Name, Category Title, URL Segment, and Activate On to the Category.
Save the newly created Category by clicking **Save**.
Click the **Products** finger tab.
Ensure the **Use Dynamic Rules** toggle reflects **Yes**.
Select the **Rule Type** from the drop-down.
Configure the rule using the contextual **Source Data Table** and **Fields**.
If there are more rules that you wish to create, repeat steps 9-10.
Click **Save** to save the new rule.
In the Primary Navigation, go to **Marketing** \> **Indexing**.
In the **Category** section, click **Full Rebuild** to rebuild the newly created category.
Click the **Product** section, click **Partial Rebuild** to rebuild the website's product search index and make it so products are visible and searchable.