Take the wikipedia definition:
Agile software development is an approach to software development under which requirements and solutions evolve through the collaborative effort of self-organizing and cross-functional teams and their customer(s)/end user(s).
so what is this saying? It's saying that groups of developers work on changing problems and communicate with each other. that doesn't give any description on how problems are solved, the structure of teams (aside from there being groups), the management, the target audience for agile, or even how it's implemented. The entire wikipedia article reads like this. like an advertisement.
Now I'm no newbie to software engineering, and I can clearly see that this definition is meant to stir as many buzzwords as possible, meaning that its meant to appeal to upper management.
which brings me to my question, why are all the definitions for agile development so handwave-y, and where can i find a simple, but technical description of agile?