Vue 3

1. Composition API: Provides more flexibility and organization of code with reusable component logic.
2. Reactivity System: Revamped reactivity system for better performance and smaller bundle sizes.
3. Teleport: Allows rendering component content at a different place in the DOM tree, useful for overlays and modals.
4. Faster Mounting: Improved component mounting times for faster rendering.

Before learning Vue 3, it's beneficial to have:

1. HTML/CSS/JavaScript: Strong foundation in HTML for markup, CSS for styling, and JavaScript for scripting.
2. Basic Vue.js Knowledge: Familiarity with Vue.js fundamentals including components, directives, and data binding.
3. Understanding of Single-Page Application (SPA) Concepts: Knowledge of SPA architecture and routing concepts.
4. ES6+: Understanding of ES6+ features such as arrow functions, classes, and modules, which are commonly used in Vue 3 projects.

By learning Vue 3, you gain the following skills:

1. Vue.js Proficiency: Mastery of Vue.js framework concepts, including components, directives, and reactivity.
2. Composition API: Ability to use the Composition API for organizing and reusing component logic.
3. Reactive Programming: Understanding of reactive programming principles and Vue's reactivity system.
4. Component-Based Architecture: Skills in building applications with a modular and reusable component-based architecture.