Holograms are made 100% using packets, there are no real entites in your worlds which gives us a lot of possibilities when it comes to per-player behaviour.
Holograms can have multiple pages.
Holograms can be clickable with many click action options.
Hologram lines have a system for text animations.
Hologram lines can be offset off the parent Hologram center.
You can setup permissions to view Holograms or Hologram lines.
There are a few preset features like Damage & Heal displays.
And much more...
DecentHolograms is a plugin made for server admins, therefore it doesn't need multiple different permission nodes for different actions. So, there is just one permission node you need to be able to do everything with DecentHolograms. And that is:
This is a simple tutorial to get started with editting holograms. Full list of all commands is here.