This tutorial discusses the use of Placeholders in Resource Definitions to dynamically allocate values to configuration using the Humanitec Platform Orchestrator. It aims to educate platform engineers and developers on how to efficiently manage Resource Definitions with Placeholders, reducing the need for multiple definitions. Resource Definitions are used to provision resources, define matching criteria, and create various types of resources such as Terraform-based resources. A static namespace Resource Definition was created with placeholders to allocate values dynamically, and a global Matching Criteria was applied to all Applications. A workload was then created and deployed to verify the correct namespace allocation. The tutorial emphasizes the importance of understanding Resource Definitions and Placeholders for efficient resource management, allowing for flexible and dynamic resource allocation.