A Software Development Kit, or SDK, is a collection of tools, libraries, and documentation that developers use to create applications for specific platforms or frameworks. It simplifies the development process by providing pre-built components and functions, allowing developers to focus on building unique features rather than starting from scratch. SDKs are often tailored for particular programming languages or operating systems, such as Android or iOS. They may include sample code, debugging tools, and application programming interfaces (APIs) that facilitate communication between different software components. Overall, SDKs help streamline the development process and enhance productivity.