how does morale work?

[lilmoon]

hi can somebody explain how morale works and what it does?

I avoid to have armies that dont like each other and in fact I think I see a smily face below my unit, but I am not sure if they are neutral or happy...

- how can I check?
-how can I make them happy?
-what does high morale change?
-why my druid stuff has rebelled against me? I didnt do anything bad.

please let know thank you