I see a lot of AI-generated explanations comparing grid-following (GFL) and grid-forming (GFM) inverters, but many still fail to help build a mental model.
I really like Sam Maleki, Ph.D. , P.Eng. approach. Imagine a football match: the player is the inverter, and the coach is the control system.
With a GFL inverter, the player is completely dependent on the coach. The coach watches the game and tells the player exactly what to do. In a real match, this would quickly become chaotic—the player might not even touch the ball until the coach gives a specific instruction on how to touch it.
With a GFM inverter, the player gains independence. They understand the game, react to what is happening, and make decisions on their own even if the coach suddenly collapses. Finally, they can actually play football.
This is probably the clearest and most intuitive explanation of GFL versus GFM that I have seen so far.