The main difference - quite literally - is the word scaling. Agile is a phenomenon that we discussed earlier, and it's the common expectation of how teams should organize themselves today. No one questions that complexity and uncertainty do not go well together with a waterfall approach to team organization. We still have a lot of teams with command-and-control leaders out there; some learned it this way and others still think this is the way business works.
But most of the non-agile teams still at least claim to be agile. They are "scrum but "or "Kanban but."
So for one team, Scrum or Kanban seems to be the way to go. High fives all 'round if your organization has already mastered daily standups, is doing sprints, backlog grooming, sprint planning, and retrospectives. Now, what if you even want to be able to do them fully remote, on-site or hybrid? This poses yet another form of complexity to master. However, let's assume that your team is at it and you're on the right track. That's of course all very likely if you read this anyway.
Scaling Agile now means that you try to instil this agile mindset generally into the whole organization. Business Agility is just another bogus term for the same thing. Your approach to business should be adaptable and iterative. That means that your people are open-minded, work in teams, work together, foster transparency, and share a purpose to advance the company. While this may sound like a dream world situation in a lot of large organizations, there are very successful companies out there who do exactly this.
If they find routine and repetitive jobs, they set out to automate and eliminate them. There is no politics about protecting the status quo. An agile company will embrace change and will not shy away to even experiment with significant organizational changes.