Introduction to web APIs

Information sharing and processing are in huge demand on the web and across web-based services. A web API is a service available on the web that provides access to resources such as raw data, filtered information, and embedded and dynamic content, normally in a ready-to-use and exchangeable format such as JSON, CSV, or XML.

Information exchange or transfer is the core purpose of web APIs. We can consider an API as a web- or browser-based service or user interface (UI) for retrieving, sharing, or accessing information based on requests made to a web server or API provider. With plenty of security-related vulnerabilities, many providers ask for authentication in the form of an API key (a unique block of identification with a certain length that identifies the user or client with the API or server) or some code to make API processing more efficient and effective.

Web APIs are not dependent on any single programming language (such as ASP, PHP, or JSP); users...