Transparency is used to define whether or not a surface can be seen through. In Unreal Engine, Transparency and Opacity have two distinct meanings. In the real world, these properties are referred to as Transparency or Opacity and the two often used interchangeably to describe the same thing.
When creating certain surface types such as water or glass, you need the ability to make the surface not only see through, but also give the surface a sense of depth and color.
