The Adobe PDF SDK is a software development kit that allows developers to integrate PDF functionalities into their applications. It provides tools and APIs for creating, manipulating, and rendering PDF documents, making it easier to work with this widely used file format. With the Adobe PDF SDK, developers can automate tasks such as document generation, form filling, and digital signatures. This SDK supports various programming languages and platforms, enabling seamless integration into web and mobile applications, enhancing user experience with PDF capabilities.