HTTP methods, originally developed for web browsers to display web pages and submit forms, are now vital for SaaS integrations. The HTTP protocol has evolved since its inception in 1991, expanding from the simple GET method to include others like POST, PUT, DELETE, and more, with each serving different functions such as retrieving, modifying, or deleting data. These methods are crucial for API interactions, with REST APIs utilizing a variety of methods like GET, DELETE, PUT, PATCH, and POST to manage resources, while RPC and SOAP APIs primarily use POST to call remote procedures. GraphQL APIs, differing in function, support both POST and GET, although POST is more commonly used to avoid complications with long request strings. Each API type implements these methods uniquely, but the fundamental requirement remains that they employ at least one HTTP method to facilitate data transfer, underscoring their importance in modern web and application interfaces.