What is React, why is it needed, and what tasks does it solve? When should you use React, and when is plain JavaScript enough?

React is a JavaScript library for building user interfaces, especially single-page applications. It allows creating UI from components that manage their own state and efficiently update the DOM using a virtual DOM.

Tasks that React addresses:

• Simplifying the development of complex interfaces with dynamic data updates.
• Reusing components.
• Managing application state.
• Optimizing DOM updates for better performance.

When to use React:

• If the application is large, with many interactions and a dynamic UI.
• When scalability and code reuse are important.
• If you need an ecosystem of tools and libraries around React.

When plain JavaScript is enough:

• For simple or static pages with minimal interactivity.
• If the project is small and does not require complex state management.
• When you want to avoid an additional layer of abstraction and dependencies.

Example: for a simple feedback form, plain JS may suffice, but for a complex dashboard with many components, React would be more convenient.