This graphic shows all the significant gravitational-wave (GW) events the LVK detected from O1-O4a with their time, distance, mass, and Signal to Noise Ratio (SNR) represented by different features of the graphic. SNR is a measure of the 'strength' of the signal in the detectors. The higher the SNR, the better. This way of showing detections highlights how our sensitivity to GWs has improved with time (since the O4a "slice" of the graphic is much more densely populated than O1).