Lamps are inserted as separate objects by Shift + A >> Lights .
The brief explanation of light types is included in this video:
Blender offers four types of lamps -- point, spot, area and sun. The detailed description of each type and its settings may be found in the official reference manual:
link Light objects
In practice, the lamps are used to create realistic illumination of a certain object. In such case we use three types of lights:
- key light -- this is the main light, which determines how intense is the object illuminated
- fill light --this light softens the intensity of the shaded parts
- rim light -- this light creates an outline around the objects so it is distinguishable in the scene
As we have seen, lamps affect the scene locally, i. e. the illumination depends on the position/direction of the light. However, Blender also offers global settings for illumination, which are introduced in this video:
Focus on the parts about ambient occlusion and bloom. The parts about depth of field may be omitted. Also, the parts about subsurface scattering and screenspace reflections are subject of the materials lesson, so they may be omitted for now.
Also it is useful to learn about output settings at the end of the video. These will be needed for creating renders for your projects.
The last part of the lesson is the presence of shadows which are casted by light sources. The shadows offer several settings which are described in the following part of the manual
The shadows are set globally and the settings are adjusted in the rendering tab: