Whether you look at Vue, Solid, or Angular, most frameworks within the Javascript ecosystem have some representation of a signal. A signal is a reactive primitive that tracks its consumers, allowing for fine-grained reactivity to boost browser performance and minimize page rerenders. But where do they come from? And what is "fine-grained reactivity"? In this talk, we will go through the history of signals: did you know signals are older than the internet? And discuss how they are being applied across the Javascript ecosystem to help us build faster, better applications for our end users.