How to control enemy fort in heroes of the storm? Only Ragnaros can control enemy fort in heroes of the storm? What is keep in heroes of the storm?

How to control enemy fort in heroes of the storm?
Only Ragnaros can control enemy fort in heroes of the storm?
What is keep in heroes of the storm?

Yes, Rag is the only hero who can “become” an enemy fort after it’s been destroyed. Abathur can use friendly structures as towers for own abilities.
Forts are the outer defences and keeps are the inner (closer to the core). There are no differences in how they function but keeps have more hp, deal more damage and award more xp for destroying it.
Also destroying a fort will give your team passive xp gain. As far as I am aware keeps will not.

What is towers?
Thank you.