What is a mana link?

Sometimes after a **NEWS FLASH*** when a wizard takes a town, I lose 1 point of max health. Other times nothing happens. Even when I beat the wizard I don't get the point of health back.
It's really hard to find anything concrete about Shandalar mechanics. But from what I understand this has to do with a mana link to the town. But I don't know what a mana link is...
I used to play this game as a kid and I feel no closer to understanding it as an adult.
Any help is appreciated.
It's really hard to find anything concrete about Shandalar mechanics. But from what I understand this has to do with a mana link to the town. But I don't know what a mana link is...
I used to play this game as a kid and I feel no closer to understanding it as an adult.
Any help is appreciated.