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.
There are different Types of Lights available in Unity and Unreal Engine such as Point Lights, Spot Lights, Directional Lights
https://dev.epicgames.com/community/learning/tutorials/2Kb1/unreal-engine-tip-16-unity-unreal-switching-type-of-lights