Meteor JS

1. Full-Stack JavaScript: Develop both client and server-side code using JavaScript.

2. Real-Time Communication: Facilitates real-time data synchronization between client and server.

3. Reactive Data: Automatically updates UI in response to data changes for a smooth user experience.

4. Build System: Automates tasks like bundling and minification for efficient deployment.

Before learning Meteor.js, it's beneficial to have:

1. JavaScript Proficiency: Solid understanding of JavaScript fundamentals, including ES6+ features.

2. HTML and CSS: Familiarity with HTML for structuring web pages and CSS for styling.

3. Node.js Knowledge: Basic knowledge of Node.js and its ecosystem since Meteor builds on top of Node.js.

4. Database Concepts: Understanding of database concepts, especially MongoDB, which is commonly used with Meteor.

By learning Meteor.js, you gain:

1. Full-Stack Development: Ability to develop both client and server-side components using JavaScript.

2. Real-Time Web Applications: Skills to build real-time, reactive web applications with seamless data synchronization.

3. Efficiency: Streamlined development process with built-in features like automatic code reloading and data synchronization.

4. Cross-Platform Development: Capability to create web, mobile, and desktop applications from a single codebase.