Lights are an essential part of every scene. While meshes and textures define the shape and look of a scene, lights define the color and mood of your 3D environment. You’ll likely work with more than one light in each scene. Making them work together requires a little practice but the results can be quite amazing.
Lights can be added to your scene from the GameObject->Light menu. You will choose the light format that you want from the sub-menu that appears. Once a light has been added, you can manipulate it like any other GameObject. Additionally, you can add a Light Component to any selected GameObject by using Component->Rendering->Light.
There are many different options within the Light Component in the Inspector.
By simply changing the Color of a light, you can give a whole different mood to the scene.
Unity supports different Rendering Paths. These paths affect mainly Lights and Shadows, so choosing the correct rendering path depending on your game requirements can improve your project’s performance. For more info about rendering paths you can visit the Rendering paths section.