Left panels: Example of flaring stars with different activity levels. Red curves denote flares. Blue curves are fitted baselines. Black curves are the relative flux. Right panel: Rotation–flaring activity relationship. The x axis is the Rossby number (Ro; the ratio of the rotation period to the global convective turnover time), which has removed the influence of stellar mass. The shapes refer to the following star types: circle = dwarf; triangle = binary; and five-pointed star = subgiant. The green line (Ro = 0.08) separates the saturated and unsaturated regimes. The Sun is marked with an ⊙ symbol.