Serverless libraries are a type of library that allow developers to create applications without having to manage any servers. They provide an easy way for developers to deploy their code and scale it as needed. Serverless libraries can be used in frontend development by providing a platform for hosting, deploying, and managing the application's code. This allows developers to focus on the development of their application instead of worrying about server management. Additionally, serverless libraries can help reduce costs associated with hosting and scaling applications since they are hosted on cloud providers such as AWS or Azure.