Parse Server is an open-source backend platform that allows developers to build and manage applications without needing to create a server from scratch. It provides essential features like user authentication, data storage, and push notifications, making it easier to focus on app development. Originally developed by Parse, a company acquired by Facebook, Parse Server can be deployed on various cloud services, such as AWS or Heroku. It supports multiple programming languages and offers a flexible architecture, enabling developers to customize their applications according to specific needs.