Components are the basic units of composition in React.

Every component accepts a set of keyed input parameters known as "props" that are initialized by the constructor. Once a component is mounted, the props can be mutated using setProps or replaceProps.

Every component is capable of the following operations:

mountComponent Initializes the component, renders markup, and registers event listeners.

receiveComponent Updates the rendered DOM nodes to match the given component.

unmountComponent Releases any resources allocated by this component.

Components can also be "owned" by other components. Being owned by another component means being constructed by that component. This is different from being the child of a component, which means having a DOM representation that is a child of the DOM representation of that component.