BRIO Direct Light is the default lighting when you begin a project. The Light Set library contains a variety of pre-built lighting setups you can adjust to fit your scene.
Read more about the light set library here.
You can also add light sources individually and save the light set to your personal library.
Individual lights can be added using the lightbulb button in the tools menu.
Light options include:
Ambient Light: Foods even light across the scene. Envelopes the entire scene, cannot be rotated.
Direct Light: Can be adjusted to point in the desired direction. Mimics the Sun.
Area Light: Casts light within the bounds of a defined, rectangular area. Similar to a Photographers Soft Box lights.
Point Light: Single point light source such as a light bulb.
Spot Light: Casts a smaller ring of light in a specific direction, which can be controlled by rotating and moving the light.
The colour and intensity of lights can be modified in the properties panel when selected.
Image-based lighting can also be used to add environmental light to your scene, which you can read about here.