In ReactJS, a component is a fundamental building block of the user interface (UI). It is an independent and reusable code block that encapsulates a part of the UI. Components in React can be thought of as custom, self-contained elements that you define. They behave similarly to JavaScript functions but work in isolation and return HTML via a rendering function[1][4][8].
Components come in two primary types: Class Components and Functional Components.
Class Components are ES6 classes that extend from React.Component and include a render() method that returns JSX (a syntax that resembles HTML). They can manage private data (state) and provide more complex UI logic and lifecycle methods, which are hooks that allow execution of code at set points during a component's lifecycle[3][5][6][7].
Functional Components, on the other hand, are simpler functions that accept props and return JSX. They are stateless by default but can use React Hooks to utilize state and other React features[1][4][11].
Why Use Components?
Reusability: Components are designed to be reusable, which means you can define a component once and use it in multiple places in your application. This reduces code duplication and leads to cleaner, more maintainable code[4][8].
Encapsulation: Components encapsulate their behavior and styling, meaning they keep the code for a particular part of the UI separate from the rest. This encapsulation makes it easier to debug and manage the UI[4][8].
Modularity: Using components allows developers to think about each part of the UI in isolation, making it...
