Summary

An API is a set of rules and protocols that enables one software application to interact with another. APIs facilitate communication between different software systems, allowing them to exchange data and functionality. There are different types of APIs, including web APIs, library APIs, and operating system APIs.

API operations can be categorized as idempotent or non-idempotent. Idempotent operations can be repeated multiple times without them changing the result, making them safer for retries in case of failures. Non-idempotent operations, on the other hand, may yield different results with each execution.

APIs often use HTTP verbs to define the operation that should be performed. Common HTTP verbs include GET (retrieve data), POST (create data), PUT (update data), and DELETE (remove data).

API design involves considering aspects such as endpoint structure, data format (typically JSON or XML), error handling, versioning, and authentication. A well-designed API promotes...