About baking lights.

Hello, can anyone explain to me, how does this really work?
As I understand, when baking, unity takes everything around light source (i.e. walls, floors etc.) and looks how light affects them, and kinda save those new textures (with shadows and light on them) as a replacement to standart ones, right?

But what’s happening with light itself? shall I, like, disable shadows or I gotta leave the shadows on, but unity will not process shadows from that source onto surroundings, it will only calculate moving objects (player)?

If you want your light to affect the player(if it is a 3d person view) you can bake light probes. Actually, I can’t say if the shadow cast by the player will be visible, but in any case you can use a fake shadow or dual lightmaps. What is the better only tests can show.