In React, everything you build are components. Imagine a component as a LEGO brick; by combining components together, you get a complete UI. A button can be a component, an input field can be another component.
Many developers use the terms "element" and "components" interchangeably. Generally speaking, you should use "element" when referring to HTML elements, and "component" when describing React components.
Each component contains its own HTML, CSS, and JavaScript, so it is independent of other components. This includes methods to run when the component is first rendered on-screen, and methods to run when it is removed from view (collectively, these are called lifecycle methods).
Components can be combined to form new components. ...
