1. Supported Features: Postman is primarily focused on API testing and offers a wide range of features for this purpose. It allows users to send requests, manage environments and variables, and automate workflows. On the other hand, ngrok focuses on creating secure tunnels to expose localhost to the internet, making it easier to test webhooks and other internet-facing functionalities.

2. API Documentation: Postman provides a comprehensive platform for documenting APIs, allowing developers to create detailed documentation with ease. It includes features such as interactive documentation, example responses, and the ability to share documentation with other team members. In contrast, ngrok does not provide specific features for API documentation.

3. Authentication and Authorization: Postman offers various authentication methods such as OAuth, API keys, and JWT tokens. It allows developers to easily set up and manage authentication for their APIs. Ngrok, on the other hand, does not provide built-in authentication and authorization mechanisms. It focuses more on tunneling functionality rather than authentication.

4. Collaboration and Teamwork: Postman includes collaboration features that allow team members to work together on API development and testing. It allows for sharing of collections, environments, and documentation with other team members. Ngrok, on the other hand, does not offer specific collaboration features. It is more oriented towards individual developers and their local development environments.

5. Pricing and Usage: Postman offers both free and paid plans, with the paid plans providing additional features such as team collaboration and advanced request features. On the other hand, ngrok has a free plan that provides basic functionality but restricts certain features to paid plans. The pricing and usage models of the two tools differ based on their specific offerings.

6. Network Configuration: Ngrok simplifies the process of creating secure tunnels by handling the network configuration automatically. It eliminates the need for manual port forwarding or opening firewall settings. Postman, on the other hand, requires the proper network configuration to establish connections and send requests to APIs.

In summary, Postman and ngrok have key differences in their supported features, API documentation capabilities, authentication and authorization mechanisms, collaboration and teamwork functionalities, pricing and usage models, and network configuration requirements.