sometimes, one or more parameters may be appended to the URL as a query string and meant to be processed by the script: http://example.com/hello.php?name=FirstName&marks=75
The modern web uses a route-based approach, which makes the URL as http://example.com/FirstName/75. The URL has three distinct parts: the protocol (http:// or https://) followed by the IP address or hostname. The remaining part of the URL after the first / after the hostname is called the path or endpoint.
API Docs
FastAPI's design follows the OpenAPI specification (OAS) for API creation and declaration of path opeartions, parameters, etc. It also autogenerates the documentatin of data models with JSON Schema. JSON schema defines a JSON-based media type called "application/schema+json". It is a format for describing the structure of JSON data.
By default, FastAPI uses Swagger UI and Redoc
Path Parameters
This path can be a mixture of fixed part and a variable part.
Generally, the fixed part referes to a collection of resources available to the server, and the variable part (which may have one or more values) is used to locate or retrieve a specific resource from the collection.
As already stated, the FastAPI application object acts as a router, directing the incoming request from the client to the appropriate handler function. It checks the request URL matches with the pattern declared in which opeartion decorator.
Query Parameters
If a certain operation function (also called a view function) below the path decorator has some parameters in addition to the placeholders in the URL pattern, FastAPI deems them to be query parameters.
Path and Query has a lot of configurations. See chap2/app_fastapi.py for more examples.