The Tools 1 (upper-left) quadrant for viewport lighting appears when a single light object is selected in the scene.
When on, the light object affects only ambient light in viewports.
When on, the light object affects specular color in viewports.
When on, the light object affects diffuse color in viewports.
Turns on shadows for the light, for viewport display. This setting does not change the value of the light’s Shadows toggle, so it doesn’t affect the rendered scene.
Toggles whether the light is on or off.
This option appears only if you have selected a target light. Choose it to select the light’s target and reposition it.