Here is a summary of the provided text in one paragraph: An API (Application Programming Interface) works like a messenger, carrying requests to their destination and resulting in output. APIs are used by apps to fetch data from servers, such as weather updates or social media posts, instead of creating their own systems. The concept of an API is similar to a waiter in a restaurant, who takes orders and passes them to the kitchen. An API provides a way for users to interact with services without exposing sensitive data or creating their own service. API documentation serves as a guide explaining how to use a given API, while HTTP request methods such as GET, POST, PUT, and DELETE determine the type of interaction between a client and server. The text also explains how to make an API request using curl, a command-line tool, and introduces Twilio's Programmable Messaging API for sending SMS messages. Additionally, it discusses the difference between APIs and SDKs (Software Development Kits), highlighting that SDKs are pre-written code resources that simplify the process of building software by abstracting away API details.