Scenes in Unity are like separate chapters in a book, each containing specific elements and gameplay experiences. You can think of them as individual levels, menus, cutscenes, or other segments of your game world. Scenes allow you to organize and manage different parts of your game independently, making it easier to work on and maintain large projects.

using UnityEngine.SceneManagement:

This line includes functionality from Unity's SceneManager class, which allows you to manage scenes in your game, such as loading new scenes, reloading the current scene, unloading scenes, and getting information about the current scene.

SceneManager.LoadScene

SceneManager.LoadScene is a function provided by Unity's SceneManager class, which allows you to load scenes within your Unity project. When you call SceneManager.LoadScene, you provide it with the name or index of the scene you want to load. You will find the index of each scene in the build panel after adding the open scene:

This function is commonly used to transition between different parts of your game, such as moving from a menu scene to a gameplay scene or from one level to another.

You can also load a scene using its name:

Application.Quit:

Application.Quit is a function provided by Unity's Application class, which allows you to quit the application or game. When you call Application.Quit, it immediately terminates the application. This function is typically used in scenarios where you want to provide an option for the player to exit the game, such as in a pause menu or at the end of the game.

Build Panel in Unity

The Build Panel in Unity is a section of the Unity Editor that allows you to build and deploy your project to various platforms.

To access the Build Panel, go to File > Build Settings in the Unity Editor.

In the Build Panel, you can add scenes to your build settings, specify build options, and build your project for different target platforms (e.g., Windows, macOS, Android, iOS). You can also switch between different build configurations, such as development builds or release builds, and adjust other settings related to the build process.

Once you've configured your build settings, you can click the Build button to generate the executable or package for your chosen platform.