MongoDB is an open source document-oriented NoSQL database system written in the C++ programming language. It manages collections of BSON documents. wikipedia.org

MySQL is a relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases. wikipedia.org

"Express is a minimal and flexible Node.js Web application framework, providing a robust set of features for building single-page, multipage, and hybrid Web applications"

Vue.js is a library for building interactive web interfaces. The goal of Vue.js is to provide the benefits of reactive data binding and composable view components with an API that is as simple as possible. wikipedia.org

React is an open-source JavaScript library for creating user interfaces that aims to address challenges encountered in developing single-page applications. wikipedia.org

The front end is responsible for collecting input in various forms from the user and processing it to conform to a specification the back end can use. The front end is an interface between the user and the back end. wikipedia.org

Node.js is a software system designed for writing highly-scalable internet applications, notably web servers. Programs are written in JavaScript, using event-driven, asynchronous I/O to minimize overhead and maximize scalability. wikipedia.org