In the path, you pass userId. Why exactly in the path? Where else can it be passed?

Passing userId in the path (for example, /users/123) is often used because:

• It aligns with RESTful style, where resources are identified in the URL.
• Convenient for caching and logging.
• Easy to read and understand.

Alternative ways to pass userId:

• In query parameters: /users?userId=123 — convenient for filtering or searching.
• In the request body: usually for POST/PUT requests, when data is sent in JSON or form-data format.
• In headers: rarely, but possible, for example, to pass identifiers in API.

The choice depends on the context and semantics of the operation. Path is usually for resource identification, query for request parameters, body for data, and headers for metadata.