In this React Native video lesson we want to learn How to Fetch Data in React Native, for fecting data in React Native we want to use useEffect Hook. in React Native useEffect is a Hook that allows developers to run side effects such as fetching data, updating the DOM or setting up event listeners in functional components. it is similar to the lifecycle methods such as componentDidMount and componentDidUpdate in class components.

useEffect Hook is called after every render of the component and can be used to perform any cleanup or setup tasks that are required. it accepts two arguments,  a function that contains the side effect code and an optional array of dependencies that control when the effect should be re run.

These are some key features of the useEffect Hook:

1. Side effects: useEffect Hook is used to perform side effects, such as fetching data from an API or updating the DOM.
2. Dependency array: useEffect Hook takes an optional array of dependencies that control when the effect should be re run. if any of the dependencies change between renders the effect is re run.
3. Cleanup function: useEffect Hook can also return cleanup function that is called when the component is unmounted or when the effect is re run.
4. Asynchronous code: useEffect Hook can be used with asynchronous code such as promises or async/await functions to perform side effects.
5. Multiple effects: single component can have multiple useEffect Hooks that perform different side effects.

So we can say that useEffect Hook is powerful and flexible tool for performing side effects in functional components in React Native. it allows developers to easily manage the lifecycle of components and perform side effects in clean and easy way. by using useEffect Hook developers can create more modular and reusable code and avoid the complexities of managing side effects in class components, in the React Native video we practically learn how to fetch data in React Native