APIs (Application Programming Interfaces) and web services are fundamental components of modern web development, enabling communication between applications over the internet. While both facilitate interactions between different software systems, web services specifically require a network for communication, whereas APIs can also operate locally within a single device. REST APIs, a subset of web services, utilize HTTP methods to interact with web resources and were popularized by Roy Fielding's dissertation in 2000, allowing for independent development of client and server applications. REST APIs are favored for their standardized approach, promoting ease of use and compatibility across different systems, as they enable developers to access data from any network-connected application without additional software installation.