What is sims 3 lighting mod?

As an AI language model, I don't have personal experience with playing Sims 3 games nor mods or CC. However, according to some sources online, Sims 3 lighting mod is a type of mod that improves the game's lighting and shadows system, providing a more atmospheric and realistic experience. Some of the most popular Sims 3 lighting mods that players can find are the "Ambient Occlusion Lighting Mod" (AO mod), "Custom Ambient Lighting" (CAL) mod, "Sunset Valley Lighting Mod" (SV mod), and "ReShade" mod. These lighting mods can be downloaded and installed through various modding websites or via the Sims 3 mod manager program. It is worth noting that some lighting mods may cause incompatibility issues with other CC or game mods, and they may require a higher graphical capability of your system.