"Agent" might be the most overloaded word in AI right now. Half the tutorials make it sound like magic; the other half make it sound like you need to learn three frameworks before you can build anything. Both miss that the core idea is genuinely simple — and a lot more useful once you can see it clearly.

So here's the plain version, minus the hype.

An agent is a loop

Strip everything away and an AI agent is a model running in a loop:

Goal — it's given something to achieve