An SDK (software development kit) is a programming library made to serve developers and the development process, providing tools that help developers interact with APIs using pre-built functionality, enabling quicker and safer software development. This allows for easier access to APIs without manual operations, reducing errors and increasing readability. SDKs benefit both end users and API owners by ensuring correct usage, reducing costs, and improving speed and code maintenance. Additionally, they provide better understanding of how to use an API through semantically-named functions, parameters, and types, making it easier for developers to invoke methods as they become readily available in development environments.