What are JavaScript frameworks and how do they help in web development?

JavaScript frameworks like React, Vue, Svelte, and Angular allow developers to create complex user interfaces by breaking them into manageable components. Each component has its own lifecycle and state, enabling a more organized approach than viewing a webpage as just HTML, CSS, and classes. Frameworks transform how we structure applications - a search box, menu, or form becomes a separate component with specific functionality. This component-based architecture helps developers create dynamic, well-organized applications where all elements work together cohesively. The choice of framework depends on personal preference, with each offering its own ecosystem of supporting software.