ELI5: What's the significance of characters in movies giving each other cigarettes?

Pretty stupid question so sorry about that. I've never smoked in my life and don't really know what it feels like or does for you.

So in movies, when characters who could be total strangers or even enemies, give each other cigarettes, or light each other's cigarettes, I'm a bit confused as to what the meaning is. For example, it can't be friendship because I've seen scenes where villains give hostages cigarettes even while doing bad things to them.