Postman is a commonly used tool for testing and debugging APIs. It provides a user-friendly interface for making API requests, inspecting responses, and debugging API endpoints. Unlike design or document editing tools like Photoshop, Microsoft Word, or Excel, Postman is specifically designed for API development and testing.

Fine-tuning the granularity of API throttling can ensure that resources are not overused while still providing a responsive service. Granularity refers to the level of detail at which you set throttling limits. By defining specific limits for different types of requests, you can optimize resource allocation.

ASP.NET Core is primarily used for building server-side web applications. It's a cross-platform, high-performance framework that enables developers to create robust, scalable, and efficient web applications that can run on Windows, Linux, and macOS. It's not focused on client-side JavaScript, mobile app development, or database management.

The payload of a JWT typically contains user-specific data, such as user ID or roles. It can also include other claims, like issuer, expiration date, and custom claims. These claims provide context and information about the token and are used by the receiver to make authorization decisions. The payload is not used for cryptographic purposes.

The choice between REST, SOAP, GraphQL, or gRPC for an API is influenced by various factors, such as the specific requirements of the project, the need for real-time data, existing infrastructure, and the desired level of flexibility. The phase of the moon and personal preferences are not valid criteria for making this decision.

Keeping API keys secure is crucial to prevent accidental exposure. Exposed API keys can lead to unauthorized access, data breaches, and potential misuse of your API services, compromising the security of your applications and data.

Common strategies for API versioning include URL versioning (e.g., "/v1/endpoint"), header versioning (e.g., specifying the version in HTTP headers), and content negotiation (accepting different response formats based on version). These methods allow for evolving APIs while maintaining compatibility.

The goal of API monitoring and analytics is to continuously track an API's health and usage, detect issues, and analyze data for insights. It helps ensure reliability, security, and performance while optimizing resource allocation.

ASP.NET Core ensures the scalability and performance of APIs through support for asynchronous programming. This allows APIs to handle a large number of concurrent requests efficiently by not blocking threads, making it suitable for high-demand scenarios.

The "Content-Type" header in an HTTP request can be used to specify the format of the data being requested from a Web API. It indicates the media type (e.g., JSON, XML) of the data being sent or received, allowing the server to process the request appropriately.