How does Chained Fortification Work?

I'm trying to figure out whether chained fortifications means I can only move one army per turn, one army from each territory per turn, one army into each territory per turn, or one group of armies from a single territory to another single territory.

Chained means you have one free move at the end of your turn of how many troops you want from one of your territories to another one as long as they are connected by a "chain" of your color territories. In other words you can fortify how far you want through your own territories.

It is opposite to "adjacent" that means you can only fortify from one territory to another one that is adjacent. And then you also have "unlimited" that is the same as "chained" but rather than one move you can do how many moves you want.

So then, for example, in chained fortifications, I could move five armies from North Africa to South Africa as long as also I occupied Congo, but then I couldn't move anything anywhere else afterwards, yes?

yes

Only in "Unlimited" fortification can you move troops more than once in a turn, but again the troops have to be Chained / Linked.