Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.
Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Kakao platform provides various services such as Kakao Talk, Kakao Talk Channel, Kakao Story as well as Kakao Pay, Kakao Commerce, Kakao Page provided by the subsidiaries. Users can use all Kakao platform services with a united account called Kakao Account.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
React is an open-source JavaScript library for building user interfaces or UI components.