Can you describe the key characteristics of RESTful API and how they differ from other ways of interacting with services?

RESTful API is an architectural style for creating web services based on REST (Representational State Transfer) principles. Key characteristics of RESTful API:

• Client-server architecture: clients and servers are separated, allowing independent development.
• Stateless: each request from the client to the server must contain all necessary information; the server does not store state between requests.
• Cacheability: responses can be cached to improve performance.
• Uniform interface: use of standard HTTP methods (GET, POST, PUT, DELETE) and standard response codes.
• Resource hierarchy: resources are identified by URIs, and operations on them are performed via HTTP methods.
• Layered system: architecture can include intermediate servers, proxies, and load balancers.

Differences from other interaction methods:

• Unlike SOAP, REST is simpler, does not require complex protocols and formats (usually JSON or XML).
• Unlike RPC, REST is resource-oriented rather than procedure call-oriented.

Example RESTful requests:

GET /users/123 HTTP/1.1
Host: example.com

POST /users HTTP/1.1
Host: example.com
Content-Type: application/json

{"name": "Ivan", "age": 30}

Thus, RESTful API provides simple, scalable, and standardized interaction between client and server.