A “Junior MERN Stack Developer” is an entry-level or less-experienced developer who specializes in using the MERN stack for web development. The MERN stack is a popular technology stack for building web applications, and it consists of the following components:

1. MongoDB: A NoSQL database that stores data in a JSON-like format. It is used to handle the application’s data and is particularly well-suited for handling large volumes of unstructured or semi-structured data.
2. Express.js: A back-end framework for Node.js that simplifies the creation of RESTful APIs and handling server-side logic. It provides a robust set of features for building web applications and APIs.
3. React: A JavaScript library for building user interfaces. React is used to create the front-end of the web application, handling the user interface, components, and interactivity.
4. Node.js: A JavaScript runtime environment that allows developers to run JavaScript on the server-side. It is used to build the server and handle server-side logic.