Element V/S Component

Element

A React Element is a plain JavaScript object that describes what you want to see on the UI. It represents a DOM node or a component at a specific point in time.
Elements are immutable: once created, you cannot change their properties. Instead, you create new elements to reflect updates.
Creating an element is a fast, lightweight operation—it does not create any actual DOM nodes or render anything to the screen directly.

jsx

<button id="login-btn">Login</button>

Component

A Component is a function or class that returns an element (or a tree of elements) to describe part of the UI. Components can accept inputs (called props) and manage their own state (in case of class or function components with hooks).
Components allow you to split the UI into independent, reusable pieces, each isolated and composable.

jsx

const Button = ({ handleLogin }) => (
  <button id="login-btn" onClick={handleLogin}>
    Login
  </button>
);