Chris Maiorana has a post that discusses his thoughts on Org Agenda. His discussion is mainly why you might want to use it and what you’d want to use it for. The main takeaway from his post is that Org Agenda is very flexible and customizable.
You can decide what information you want displayed in the agenda and how you want it displayed. Maiorana lists some of the ways you might want to use the Agenda or, perhaps, not use it all.
Not a bit of it resonated with me. I’ve always simply thought of the Agenda as a list of those headings in certain Org files that have an active date. The traditional way of using it is to have a TODO file or a set of files with TODO items and have those—along with their scheduled and end dates—displayed in the Agenda. I do that too but mostly I use Agenda as a report.
As I’ve mentioned before, I keep a detailed list of my daily activities and these are displayed in the Agenda. This turns out to be useful for more than just taking trips down memory lane. For example, when I have an external appointment, I record when I leave, when I arrive, when I leave the appointment, and when I get back. That way, the next time I have an appointment at the same place, I have an idea of the travel time—and therefore when to leave—and how long it will take to get back. It’s useful information to have and well worth the effort to collect it.
Of course, that’s just one way to use the Agenda and almost certainly not the most common way. But that’s the point: you can mold the agenda to be anything you want.